linux-lvm.redhat.com archive mirror
 help / color / mirror / Atom feed
* [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
@ 2009-12-30 10:18 Simon Loewenthal/NL/Tele2
  2009-12-30 10:31 ` Simon Loewenthal/NL/Tele2
  0 siblings, 1 reply; 17+ messages in thread
From: Simon Loewenthal/NL/Tele2 @ 2009-12-30 10:18 UTC (permalink / raw)
  To: linux-lvm

Dear all,

    I have a volume group that is currently using discs directly
presented from EMC e.g
/dev/disk/by-id/scsi-360060480000290300618533030313042 .

An lvdisplay -v shows these PVs:
# vgdisplay -v vg_mds
    Using volume group(s) on command line
    Finding volume group "vg_mds"
  --- Volume group ---
  VG Name               vg_mds
  System ID            
  Format                lvm2
  Metadata Areas        12
  Metadata Sequence No  4
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               1
  Max PV                0
  Cur PV                12
  Act PV                12
  VG Size               202.12 GB
  PE Size               32.00 MB
  Total PE              6468
  Alloc PE / Size       6468 / 202.12 GB
  Free  PE / Size       0 / 0  
  VG UUID               Wnk1a8-xdVf-RorP-ZxPE-Z3D9-5fp1-2o4hHs
  
  --- Logical volume ---
  LV Name                /dev/vg_mds/lvol_mds
  VG Name                vg_mds
  LV UUID                TErCZW-senu-YR3k-I25n-Tqk9-BK2k-3mQY3S
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                202.12 GB
  Current LE             6468
  Segments               12
  Allocation             inherit
  Read ahead sectors     0
  Block device           253:7
  
  --- Physical volumes ---
  PV Name              
/dev/disk/by-id/scsi-360060480000290300618533030313133    
  PV UUID               255V1X-uMZp-Lod1-3jsa-cCGd-JaNZ-v0dEXn
  PV Status             allocatable
  Total PE / Free PE    539 / 0
  
  PV Name              
/dev/disk/by-id/scsi-360060480000290300618533030313131    
  PV UUID               RU5WZK-G3hY-lXCD-F6Kj-PcJA-DcbE-iV17P7
  PV Status             allocatable
  Total PE / Free PE    539 / 0
  
  PV Name              
/dev/disk/by-id/scsi-360060480000290300618533030313046    
  PV UUID               c3DVym-lzdw-MgS6-acQI-BcUD-UOGq-iG6hSe
  PV Status             allocatable
  Total PE / Free PE    539 / 0
  
  PV Name              
/dev/disk/by-id/scsi-360060480000290300618533030313044    
  PV UUID               d7VD54-KmXZ-t8eX-dvph-9lSp-ym03-Lc62sI
  PV Status             allocatable
  Total PE / Free PE    539 / 0
  
  PV Name              
/dev/disk/by-id/scsi-360060480000290300618533030313042    
  PV UUID               n32oAY-soe3-odYI-SAFQ-yM7v-FRaw-e9hS63
  PV Status             allocatable
  Total PE / Free PE    539 / 0
  
  PV Name              
/dev/disk/by-id/scsi-360060480000290300618533030313039    
  PV UUID               hT2hZ7-XAZr-ZUte-rzLV-kwFX-Jtih-K3OgZe
  PV Status             allocatable
  Total PE / Free PE    539 / 0
  
  PV Name              
/dev/disk/by-id/scsi-360060480000290300618533030313037    
  PV UUID               ut4fEx-R0c2-lA4y-qS3F-SYfp-Chuz-2SrvTo
  PV Status             allocatable
  Total PE / Free PE    539 / 0
  
  PV Name              
/dev/disk/by-id/scsi-360060480000290300618533030313035    
  PV UUID               BMJ8LA-b0L7-aAoK-4WqG-MLdU-s8Y8-xGib2s
  PV Status             allocatable
  Total PE / Free PE    539 / 0
  
  PV Name              
/dev/disk/by-id/scsi-360060480000290300618533030313033    
  PV UUID               uSasZ1-96rT-ngGN-Wfcr-fBNg-ceM0-GaccVU
  PV Status             allocatable
  Total PE / Free PE    539 / 0
  
  PV Name              
/dev/disk/by-id/scsi-360060480000290300618533030313031    
  PV UUID               R15yAf-t1YO-Z0Dx-4n2G-oTyD-Secp-2igMJc
  PV Status             allocatable
  Total PE / Free PE    539 / 0
  
  PV Name              
/dev/disk/by-id/scsi-360060480000290300618533030304646    
  PV UUID               nrhhx1-7AxM-VmVv-sRY5-TLR7-UAEE-wBUIMB
  PV Status             allocatable
  Total PE / Free PE    539 / 0
  
  PV Name              
/dev/disk/by-id/scsi-360060480000290300618533030304644    
  PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
  PV Status             allocatable
  Total PE / Free PE    539 / 0


I want to export this volume group and inport it again using
multipathing.  I have configured the multipathing thus,
 # multipath -ll
dm-6_010F (360060480000290300618533030313046) dm-6 EMC,SYMMETRIX
[size=17G][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:31 sdx        65:112 [active][ready]
 \_ 1:0:0:31 sdk        8:160  [active][ready]
dm-17_0012 (360060480000290300618533030303132) dm-17 EMC,SYMMETRIX
[size=4.7M][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:0  sdn        8:208  [active][ready]
 \_ 1:0:0:0  sda        8:0    [active][ready]
dm-13_0103 (360060480000290300618533030313033) dm-13 EMC,SYMMETRIX
[size=17G][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:25 sdr        65:16  [active][ready]
 \_ 1:0:0:25 sde        8:64   [active][ready]
dm-10_0109 (360060480000290300618533030313039) dm-10 EMC,SYMMETRIX
[size=17G][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:28 sdu        65:64  [active][ready]
 \_ 1:0:0:28 sdh        8:112  [active][ready]
dm-14_0101 (360060480000290300618533030313031) dm-14 EMC,SYMMETRIX
[size=17G][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:24 sdq        65:0   [active][ready]
 \_ 1:0:0:24 sdd        8:48   [active][ready]
dm-8_010D (360060480000290300618533030313044) dm-8 EMC,SYMMETRIX
[size=17G][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:30 sdw        65:96  [active][ready]
 \_ 1:0:0:30 sdj        8:144  [active][ready]
dm-15_00FF (360060480000290300618533030304646) dm-15 EMC,SYMMETRIX
[size=17G][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:23 sdp        8:240  [active][ready]
 \_ 1:0:0:23 sdc        8:32   [active][ready]
dm-11_0107 (360060480000290300618533030313037) dm-11 EMC,SYMMETRIX
[size=17G][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:27 sdt        65:48  [active][ready]
 \_ 1:0:0:27 sdg        8:96   [active][ready]
dm-4_0113 (360060480000290300618533030313133) dm-4 EMC,SYMMETRIX
[size=17G][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:33 sdz        65:144 [active][ready]
 \_ 1:0:0:33 sdm        8:192  [active][ready]
dm-9_010B (360060480000290300618533030313042) dm-9 EMC,SYMMETRIX
[size=17G][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:29 sdv        65:80  [active][ready]
 \_ 1:0:0:29 sdi        8:128  [active][ready]
dm-16_00FD (360060480000290300618533030304644) dm-16 EMC,SYMMETRIX
[size=17G][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:22 sdo        8:224  [active][ready]
 \_ 1:0:0:22 sdb        8:16   [active][ready]
dm-12_0105 (360060480000290300618533030313035) dm-12 EMC,SYMMETRIX
[size=17G][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:26 sds        65:32  [active][ready]
 \_ 1:0:0:26 sdf        8:80   [active][ready]
dm-5_0111 (360060480000290300618533030313131) dm-5 EMC,SYMMETRIX
[size=17G][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:32 sdy        65:128 [active][ready]
 \_ 1:0:0:32 sdl        8:176  [active][ready]

Device mapper reports this:
# dmsetup ls
dm-6_010F    (253, 6)
dm-17_0012    (253, 17)
dm-13_0103    (253, 13)
dm-10_0109    (253, 10)
vg00-app052    (253, 3)
vg00-xen    (253, 2)
vg00-usr    (253, 0)
vg00-var    (253, 1)
dm-14_0101    (253, 14)
dm-8_010D    (253, 8)
dm-15_00FF    (253, 15)
dm-11_0107    (253, 11)
dm-4_0113    (253, 4)
vg_mds-lvol_mds    (253, 7)
dm-9_010B    (253, 9)
dm-16_00FD    (253, 16)
dm-12_0105    (253, 12)
dm-5_0111    (253, 5)


What I do not understand is that surly when I perform a vgscan how will
it decide to query only the devices presented from the multipathd, and
ignore those presented via the dev/disk/by-id/scsi-nnnnnnnnnn?  Won't it
see two vg_mds volumes instead of only those volumes that lie on the
multipathed discs, which are the same pshycial discs as the disk/by-id?

My plan of action is currently:
    vgchange -a n vg_mds
    vgexport -m /tmp/vg_mds.map mds
    vgexport -f /tmp/vg_mds.pv mds
    vgscan
    vgchange -y a vg_mds
    vgimport vg_mds /*OR instead do it the long way on the next line*  /
        vgscan
        mkdir /dev/vg_mds
        mknod /dev/vg_mds/group c 64 0xNN0000
        vgimport -v -s -m /tmp/vg_mds.map /dev/vg_mds

I do not see how to tell it to ignore the non-multipathed disc, or has
multipathd or LVM have some preference for mutlipath discs over
non-multipathed discs, and if so then what is the logic behind the decision?

Any help to further my understanding would be gratefully appreciated.

Best wishes, S.

PS. I am using SLES, but this was the only mailinglist I found for LVM
so I subscribed to it.  I think that LVM and multipathd implementations
are reasonably similar across Linux distos. Ergo concepts here are
applicable to Suse.  The kernel I am using is a xen enabled host (not a
guest): 2.6.16.60-0.27-xen #1 SMP.

-- 
Simon Loewenthal/Tele2
GSM: +31 6 2000 5427

******** IMPORTANT NOTICE ********
Please repect the X-Reply to klunky.co.uk. PGP available 0xD86A5A17. 
S/MIME PKCS12 key available for Lotus Notes: Please ask me for it.
This e-mail (including any attachments) may contain information that is confidential or otherwise protected from disclosure and it is intended only for the addressees. If you are not the intended recipient, please note that any copying, distribution or other use of information contained in this e-mail (and its attachments) is not allowed. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message (including any attachments) from your system.
Please note that e-mail messages may contain computer viruses or other defects, may not be accurately replicated on other systems, or may be subject of unauthorized interception or other interference without the knowledge of sender or recipient. Tele2 only send and receive e-mails on the basis that Tele2 is not responsible for any such computer viruses, corruption or other interference or any consequences thereof.  It ought to be obvious that my views do not represent my employer's views.

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2009-12-30 10:18 [linux-lvm] LVM preference for multipath verses disk/by-id/scsi Simon Loewenthal/NL/Tele2
@ 2009-12-30 10:31 ` Simon Loewenthal/NL/Tele2
  2009-12-30 11:52   ` brem belguebli
  0 siblings, 1 reply; 17+ messages in thread
From: Simon Loewenthal/NL/Tele2 @ 2009-12-30 10:31 UTC (permalink / raw)
  To: simon.loewenthal; +Cc: linux-lvm

I don't think this original Email made it through to the list, but I
think I have found an solution:

In lvm.conf there is this line,
filter = [ "r|/dev/.*/by-path/.*|", "r|/dev/.*/by-id/.*|", "a/.*/" ]

If I remove the portion "r|/dev/.*/by-id/.*|", so it is rewritten as,
filter = [ "r|/dev/.*/by-path/.*|", "a/.*/" ]
...then it ought to ignore the device,
/dev/disk/by-id/scsi-360060480000290300618533030313133

Is this correct?

S.

-- 
Simon Loewenthal/Tele2


Simon Loewenthal/NL/Tele2 wrote:
> Dear all,
>
>     I have a volume group that is currently using discs directly
> presented from EMC e.g
> /dev/disk/by-id/scsi-360060480000290300618533030313042 .
>
> An lvdisplay -v shows these PVs:
> # vgdisplay -v vg_mds
>     Using volume group(s) on command line
>     Finding volume group "vg_mds"
>   --- Volume group ---
>   VG Name               vg_mds
>   System ID            
>   Format                lvm2
>   Metadata Areas        12
>   Metadata Sequence No  4
>   VG Access             read/write
>   VG Status             resizable
>   MAX LV                0
>   Cur LV                1
>   Open LV               1
>   Max PV                0
>   Cur PV                12
>   Act PV                12
>   VG Size               202.12 GB
>   PE Size               32.00 MB
>   Total PE              6468
>   Alloc PE / Size       6468 / 202.12 GB
>   Free  PE / Size       0 / 0  
>   VG UUID               Wnk1a8-xdVf-RorP-ZxPE-Z3D9-5fp1-2o4hHs
>   
>   --- Logical volume ---
>   LV Name                /dev/vg_mds/lvol_mds
>   VG Name                vg_mds
>   LV UUID                TErCZW-senu-YR3k-I25n-Tqk9-BK2k-3mQY3S
>   LV Write Access        read/write
>   LV Status              available
>   # open                 1
>   LV Size                202.12 GB
>   Current LE             6468
>   Segments               12
>   Allocation             inherit
>   Read ahead sectors     0
>   Block device           253:7
>   
>   --- Physical volumes ---
>   PV Name              
> /dev/disk/by-id/scsi-360060480000290300618533030313133    
>   PV UUID               255V1X-uMZp-Lod1-3jsa-cCGd-JaNZ-v0dEXn
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>   
>   PV Name              
> /dev/disk/by-id/scsi-360060480000290300618533030313131    
>   PV UUID               RU5WZK-G3hY-lXCD-F6Kj-PcJA-DcbE-iV17P7
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>   
>   PV Name              
> /dev/disk/by-id/scsi-360060480000290300618533030313046    
>   PV UUID               c3DVym-lzdw-MgS6-acQI-BcUD-UOGq-iG6hSe
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>   
>   PV Name              
> /dev/disk/by-id/scsi-360060480000290300618533030313044    
>   PV UUID               d7VD54-KmXZ-t8eX-dvph-9lSp-ym03-Lc62sI
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>   
>   PV Name              
> /dev/disk/by-id/scsi-360060480000290300618533030313042    
>   PV UUID               n32oAY-soe3-odYI-SAFQ-yM7v-FRaw-e9hS63
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>   
>   PV Name              
> /dev/disk/by-id/scsi-360060480000290300618533030313039    
>   PV UUID               hT2hZ7-XAZr-ZUte-rzLV-kwFX-Jtih-K3OgZe
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>   
>   PV Name              
> /dev/disk/by-id/scsi-360060480000290300618533030313037    
>   PV UUID               ut4fEx-R0c2-lA4y-qS3F-SYfp-Chuz-2SrvTo
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>   
>   PV Name              
> /dev/disk/by-id/scsi-360060480000290300618533030313035    
>   PV UUID               BMJ8LA-b0L7-aAoK-4WqG-MLdU-s8Y8-xGib2s
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>   
>   PV Name              
> /dev/disk/by-id/scsi-360060480000290300618533030313033    
>   PV UUID               uSasZ1-96rT-ngGN-Wfcr-fBNg-ceM0-GaccVU
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>   
>   PV Name              
> /dev/disk/by-id/scsi-360060480000290300618533030313031    
>   PV UUID               R15yAf-t1YO-Z0Dx-4n2G-oTyD-Secp-2igMJc
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>   
>   PV Name              
> /dev/disk/by-id/scsi-360060480000290300618533030304646    
>   PV UUID               nrhhx1-7AxM-VmVv-sRY5-TLR7-UAEE-wBUIMB
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>   
>   PV Name              
> /dev/disk/by-id/scsi-360060480000290300618533030304644    
>   PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>
>
> I want to export this volume group and inport it again using
> multipathing.  I have configured the multipathing thus,
>  # multipath -ll
> dm-6_010F (360060480000290300618533030313046) dm-6 EMC,SYMMETRIX
> [size=17G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:0:31 sdx        65:112 [active][ready]
>  \_ 1:0:0:31 sdk        8:160  [active][ready]
> dm-17_0012 (360060480000290300618533030303132) dm-17 EMC,SYMMETRIX
> [size=4.7M][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:0:0  sdn        8:208  [active][ready]
>  \_ 1:0:0:0  sda        8:0    [active][ready]
> dm-13_0103 (360060480000290300618533030313033) dm-13 EMC,SYMMETRIX
> [size=17G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:0:25 sdr        65:16  [active][ready]
>  \_ 1:0:0:25 sde        8:64   [active][ready]
> dm-10_0109 (360060480000290300618533030313039) dm-10 EMC,SYMMETRIX
> [size=17G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:0:28 sdu        65:64  [active][ready]
>  \_ 1:0:0:28 sdh        8:112  [active][ready]
> dm-14_0101 (360060480000290300618533030313031) dm-14 EMC,SYMMETRIX
> [size=17G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:0:24 sdq        65:0   [active][ready]
>  \_ 1:0:0:24 sdd        8:48   [active][ready]
> dm-8_010D (360060480000290300618533030313044) dm-8 EMC,SYMMETRIX
> [size=17G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:0:30 sdw        65:96  [active][ready]
>  \_ 1:0:0:30 sdj        8:144  [active][ready]
> dm-15_00FF (360060480000290300618533030304646) dm-15 EMC,SYMMETRIX
> [size=17G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:0:23 sdp        8:240  [active][ready]
>  \_ 1:0:0:23 sdc        8:32   [active][ready]
> dm-11_0107 (360060480000290300618533030313037) dm-11 EMC,SYMMETRIX
> [size=17G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:0:27 sdt        65:48  [active][ready]
>  \_ 1:0:0:27 sdg        8:96   [active][ready]
> dm-4_0113 (360060480000290300618533030313133) dm-4 EMC,SYMMETRIX
> [size=17G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:0:33 sdz        65:144 [active][ready]
>  \_ 1:0:0:33 sdm        8:192  [active][ready]
> dm-9_010B (360060480000290300618533030313042) dm-9 EMC,SYMMETRIX
> [size=17G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:0:29 sdv        65:80  [active][ready]
>  \_ 1:0:0:29 sdi        8:128  [active][ready]
> dm-16_00FD (360060480000290300618533030304644) dm-16 EMC,SYMMETRIX
> [size=17G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:0:22 sdo        8:224  [active][ready]
>  \_ 1:0:0:22 sdb        8:16   [active][ready]
> dm-12_0105 (360060480000290300618533030313035) dm-12 EMC,SYMMETRIX
> [size=17G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:0:26 sds        65:32  [active][ready]
>  \_ 1:0:0:26 sdf        8:80   [active][ready]
> dm-5_0111 (360060480000290300618533030313131) dm-5 EMC,SYMMETRIX
> [size=17G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:0:32 sdy        65:128 [active][ready]
>  \_ 1:0:0:32 sdl        8:176  [active][ready]
>
> Device mapper reports this:
> # dmsetup ls
> dm-6_010F    (253, 6)
> dm-17_0012    (253, 17)
> dm-13_0103    (253, 13)
> dm-10_0109    (253, 10)
> vg00-app052    (253, 3)
> vg00-xen    (253, 2)
> vg00-usr    (253, 0)
> vg00-var    (253, 1)
> dm-14_0101    (253, 14)
> dm-8_010D    (253, 8)
> dm-15_00FF    (253, 15)
> dm-11_0107    (253, 11)
> dm-4_0113    (253, 4)
> vg_mds-lvol_mds    (253, 7)
> dm-9_010B    (253, 9)
> dm-16_00FD    (253, 16)
> dm-12_0105    (253, 12)
> dm-5_0111    (253, 5)
>
>
> What I do not understand is that surly when I perform a vgscan how will
> it decide to query only the devices presented from the multipathd, and
> ignore those presented via the dev/disk/by-id/scsi-nnnnnnnnnn?  Won't it
> see two vg_mds volumes instead of only those volumes that lie on the
> multipathed discs, which are the same pshycial discs as the disk/by-id?
>
> My plan of action is currently:
>     vgchange -a n vg_mds
>     vgexport -m /tmp/vg_mds.map mds
>     vgexport -f /tmp/vg_mds.pv mds
>     vgscan
>     vgchange -y a vg_mds
>     vgimport vg_mds /*OR instead do it the long way on the next line*  /
>         vgscan
>         mkdir /dev/vg_mds
>         mknod /dev/vg_mds/group c 64 0xNN0000
>         vgimport -v -s -m /tmp/vg_mds.map /dev/vg_mds
>
> I do not see how to tell it to ignore the non-multipathed disc, or has
> multipathd or LVM have some preference for mutlipath discs over
> non-multipathed discs, and if so then what is the logic behind the decision?
>
> Any help to further my understanding would be gratefully appreciated.
>
> Best wishes, S.
>
> PS. I am using SLES, but this was the only mailinglist I found for LVM
> so I subscribed to it.  I think that LVM and multipathd implementations
> are reasonably similar across Linux distos. Ergo concepts here are
> applicable to Suse.  The kernel I am using is a xen enabled host (not a
> guest): 2.6.16.60-0.27-xen #1 SMP.
>
>   

-- 
Simon Loewenthal/Tele2

******** IMPORTANT NOTICE ********
Please repect the X-Reply to klunky.co.uk. PGP available 0xD86A5A17. 
S/MIME PKCS12 key available for Lotus Notes: Please ask me for it.
This e-mail (including any attachments) may contain information that is confidential or otherwise protected from disclosure and it is intended only for the addressees. If you are not the intended recipient, please note that any copying, distribution or other use of information contained in this e-mail (and its attachments) is not allowed. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message (including any attachments) from your system.
Please note that e-mail messages may contain computer viruses or other defects, may not be accurately replicated on other systems, or may be subject of unauthorized interception or other interference without the knowledge of sender or recipient. Tele2 only send and receive e-mails on the basis that Tele2 is not responsible for any such computer viruses, corruption or other interference or any consequences thereof.  It ought to be obvious that my views do not represent my employer's views.

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2009-12-30 10:31 ` Simon Loewenthal/NL/Tele2
@ 2009-12-30 11:52   ` brem belguebli
  2009-12-30 12:37     ` Simon Loewenthal/NL/Tele2
  2010-01-04 12:54     ` Bryn M. Reeves
  0 siblings, 2 replies; 17+ messages in thread
From: brem belguebli @ 2009-12-30 11:52 UTC (permalink / raw)
  To: simon.loewenthal, LVM general discussion and development

Hi,

see man 5 lvm.conf there is an option called preferred_names which is
well explained

It'll instruct lvm to use the preferred_names you configured in the
lvm.conf file if they exist

ie : preferred_names = "/dev/mpath/" will use /dev/mpath/XXX instead
of /dev/mapper/XXX


2009/12/30 Simon Loewenthal/NL/Tele2 <simon.loewenthal@tele2.com>:
> I don't think this original Email made it through to the list, but I
> think I have found an solution:
>
> In lvm.conf there is this line,
> filter = [ "r|/dev/.*/by-path/.*|", "r|/dev/.*/by-id/.*|", "a/.*/" ]
>
> If I remove the portion "r|/dev/.*/by-id/.*|", so it is rewritten as,
> filter = [ "r|/dev/.*/by-path/.*|", "a/.*/" ]
> ...then it ought to ignore the device,
> /dev/disk/by-id/scsi-360060480000290300618533030313133
>
> Is this correct?
>
> S.
>
> --
> Simon Loewenthal/Tele2
>
>
> Simon Loewenthal/NL/Tele2 wrote:
>> Dear all,
>>
>> � � I have a volume group that is currently using discs directly
>> presented from EMC e.g
>> /dev/disk/by-id/scsi-360060480000290300618533030313042 .
>>
>> An lvdisplay -v shows these PVs:
>> # vgdisplay -v vg_mds
>> � � Using volume group(s) on command line
>> � � Finding volume group "vg_mds"
>> � --- Volume group ---
>> � VG Name � � � � � � � vg_mds
>> � System ID
>> � Format � � � � � � � �lvm2
>> � Metadata Areas � � � �12
>> � Metadata Sequence No �4
>> � VG Access � � � � � � read/write
>> � VG Status � � � � � � resizable
>> � MAX LV � � � � � � � �0
>> � Cur LV � � � � � � � �1
>> � Open LV � � � � � � � 1
>> � Max PV � � � � � � � �0
>> � Cur PV � � � � � � � �12
>> � Act PV � � � � � � � �12
>> � VG Size � � � � � � � 202.12 GB
>> � PE Size � � � � � � � 32.00 MB
>> � Total PE � � � � � � �6468
>> � Alloc PE / Size � � � 6468 / 202.12 GB
>> � Free �PE / Size � � � 0 / 0
>> � VG UUID � � � � � � � Wnk1a8-xdVf-RorP-ZxPE-Z3D9-5fp1-2o4hHs
>>
>> � --- Logical volume ---
>> � LV Name � � � � � � � �/dev/vg_mds/lvol_mds
>> � VG Name � � � � � � � �vg_mds
>> � LV UUID � � � � � � � �TErCZW-senu-YR3k-I25n-Tqk9-BK2k-3mQY3S
>> � LV Write Access � � � �read/write
>> � LV Status � � � � � � �available
>> � # open � � � � � � � � 1
>> � LV Size � � � � � � � �202.12 GB
>> � Current LE � � � � � � 6468
>> � Segments � � � � � � � 12
>> � Allocation � � � � � � inherit
>> � Read ahead sectors � � 0
>> � Block device � � � � � 253:7
>>
>> � --- Physical volumes ---
>> � PV Name
>> /dev/disk/by-id/scsi-360060480000290300618533030313133
>> � PV UUID � � � � � � � 255V1X-uMZp-Lod1-3jsa-cCGd-JaNZ-v0dEXn
>> � PV Status � � � � � � allocatable
>> � Total PE / Free PE � �539 / 0
>>
>> � PV Name
>> /dev/disk/by-id/scsi-360060480000290300618533030313131
>> � PV UUID � � � � � � � RU5WZK-G3hY-lXCD-F6Kj-PcJA-DcbE-iV17P7
>> � PV Status � � � � � � allocatable
>> � Total PE / Free PE � �539 / 0
>>
>> � PV Name
>> /dev/disk/by-id/scsi-360060480000290300618533030313046
>> � PV UUID � � � � � � � c3DVym-lzdw-MgS6-acQI-BcUD-UOGq-iG6hSe
>> � PV Status � � � � � � allocatable
>> � Total PE / Free PE � �539 / 0
>>
>> � PV Name
>> /dev/disk/by-id/scsi-360060480000290300618533030313044
>> � PV UUID � � � � � � � d7VD54-KmXZ-t8eX-dvph-9lSp-ym03-Lc62sI
>> � PV Status � � � � � � allocatable
>> � Total PE / Free PE � �539 / 0
>>
>> � PV Name
>> /dev/disk/by-id/scsi-360060480000290300618533030313042
>> � PV UUID � � � � � � � n32oAY-soe3-odYI-SAFQ-yM7v-FRaw-e9hS63
>> � PV Status � � � � � � allocatable
>> � Total PE / Free PE � �539 / 0
>>
>> � PV Name
>> /dev/disk/by-id/scsi-360060480000290300618533030313039
>> � PV UUID � � � � � � � hT2hZ7-XAZr-ZUte-rzLV-kwFX-Jtih-K3OgZe
>> � PV Status � � � � � � allocatable
>> � Total PE / Free PE � �539 / 0
>>
>> � PV Name
>> /dev/disk/by-id/scsi-360060480000290300618533030313037
>> � PV UUID � � � � � � � ut4fEx-R0c2-lA4y-qS3F-SYfp-Chuz-2SrvTo
>> � PV Status � � � � � � allocatable
>> � Total PE / Free PE � �539 / 0
>>
>> � PV Name
>> /dev/disk/by-id/scsi-360060480000290300618533030313035
>> � PV UUID � � � � � � � BMJ8LA-b0L7-aAoK-4WqG-MLdU-s8Y8-xGib2s
>> � PV Status � � � � � � allocatable
>> � Total PE / Free PE � �539 / 0
>>
>> � PV Name
>> /dev/disk/by-id/scsi-360060480000290300618533030313033
>> � PV UUID � � � � � � � uSasZ1-96rT-ngGN-Wfcr-fBNg-ceM0-GaccVU
>> � PV Status � � � � � � allocatable
>> � Total PE / Free PE � �539 / 0
>>
>> � PV Name
>> /dev/disk/by-id/scsi-360060480000290300618533030313031
>> � PV UUID � � � � � � � R15yAf-t1YO-Z0Dx-4n2G-oTyD-Secp-2igMJc
>> � PV Status � � � � � � allocatable
>> � Total PE / Free PE � �539 / 0
>>
>> � PV Name
>> /dev/disk/by-id/scsi-360060480000290300618533030304646
>> � PV UUID � � � � � � � nrhhx1-7AxM-VmVv-sRY5-TLR7-UAEE-wBUIMB
>> � PV Status � � � � � � allocatable
>> � Total PE / Free PE � �539 / 0
>>
>> � PV Name
>> /dev/disk/by-id/scsi-360060480000290300618533030304644
>> � PV UUID � � � � � � � ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
>> � PV Status � � � � � � allocatable
>> � Total PE / Free PE � �539 / 0
>>
>>
>> I want to export this volume group and inport it again using
>> multipathing. �I have configured the multipathing thus,
>> �# multipath -ll
>> dm-6_010F (360060480000290300618533030313046) dm-6 EMC,SYMMETRIX
>> [size=17G][features=0][hwhandler=0]
>> \_ round-robin 0 [prio=2][active]
>> �\_ 0:0:0:31 sdx � � � �65:112 [active][ready]
>> �\_ 1:0:0:31 sdk � � � �8:160 �[active][ready]
>> dm-17_0012 (360060480000290300618533030303132) dm-17 EMC,SYMMETRIX
>> [size=4.7M][features=0][hwhandler=0]
>> \_ round-robin 0 [prio=2][active]
>> �\_ 0:0:0:0 �sdn � � � �8:208 �[active][ready]
>> �\_ 1:0:0:0 �sda � � � �8:0 � �[active][ready]
>> dm-13_0103 (360060480000290300618533030313033) dm-13 EMC,SYMMETRIX
>> [size=17G][features=0][hwhandler=0]
>> \_ round-robin 0 [prio=2][active]
>> �\_ 0:0:0:25 sdr � � � �65:16 �[active][ready]
>> �\_ 1:0:0:25 sde � � � �8:64 � [active][ready]
>> dm-10_0109 (360060480000290300618533030313039) dm-10 EMC,SYMMETRIX
>> [size=17G][features=0][hwhandler=0]
>> \_ round-robin 0 [prio=2][active]
>> �\_ 0:0:0:28 sdu � � � �65:64 �[active][ready]
>> �\_ 1:0:0:28 sdh � � � �8:112 �[active][ready]
>> dm-14_0101 (360060480000290300618533030313031) dm-14 EMC,SYMMETRIX
>> [size=17G][features=0][hwhandler=0]
>> \_ round-robin 0 [prio=2][active]
>> �\_ 0:0:0:24 sdq � � � �65:0 � [active][ready]
>> �\_ 1:0:0:24 sdd � � � �8:48 � [active][ready]
>> dm-8_010D (360060480000290300618533030313044) dm-8 EMC,SYMMETRIX
>> [size=17G][features=0][hwhandler=0]
>> \_ round-robin 0 [prio=2][active]
>> �\_ 0:0:0:30 sdw � � � �65:96 �[active][ready]
>> �\_ 1:0:0:30 sdj � � � �8:144 �[active][ready]
>> dm-15_00FF (360060480000290300618533030304646) dm-15 EMC,SYMMETRIX
>> [size=17G][features=0][hwhandler=0]
>> \_ round-robin 0 [prio=2][active]
>> �\_ 0:0:0:23 sdp � � � �8:240 �[active][ready]
>> �\_ 1:0:0:23 sdc � � � �8:32 � [active][ready]
>> dm-11_0107 (360060480000290300618533030313037) dm-11 EMC,SYMMETRIX
>> [size=17G][features=0][hwhandler=0]
>> \_ round-robin 0 [prio=2][active]
>> �\_ 0:0:0:27 sdt � � � �65:48 �[active][ready]
>> �\_ 1:0:0:27 sdg � � � �8:96 � [active][ready]
>> dm-4_0113 (360060480000290300618533030313133) dm-4 EMC,SYMMETRIX
>> [size=17G][features=0][hwhandler=0]
>> \_ round-robin 0 [prio=2][active]
>> �\_ 0:0:0:33 sdz � � � �65:144 [active][ready]
>> �\_ 1:0:0:33 sdm � � � �8:192 �[active][ready]
>> dm-9_010B (360060480000290300618533030313042) dm-9 EMC,SYMMETRIX
>> [size=17G][features=0][hwhandler=0]
>> \_ round-robin 0 [prio=2][active]
>> �\_ 0:0:0:29 sdv � � � �65:80 �[active][ready]
>> �\_ 1:0:0:29 sdi � � � �8:128 �[active][ready]
>> dm-16_00FD (360060480000290300618533030304644) dm-16 EMC,SYMMETRIX
>> [size=17G][features=0][hwhandler=0]
>> \_ round-robin 0 [prio=2][active]
>> �\_ 0:0:0:22 sdo � � � �8:224 �[active][ready]
>> �\_ 1:0:0:22 sdb � � � �8:16 � [active][ready]
>> dm-12_0105 (360060480000290300618533030313035) dm-12 EMC,SYMMETRIX
>> [size=17G][features=0][hwhandler=0]
>> \_ round-robin 0 [prio=2][active]
>> �\_ 0:0:0:26 sds � � � �65:32 �[active][ready]
>> �\_ 1:0:0:26 sdf � � � �8:80 � [active][ready]
>> dm-5_0111 (360060480000290300618533030313131) dm-5 EMC,SYMMETRIX
>> [size=17G][features=0][hwhandler=0]
>> \_ round-robin 0 [prio=2][active]
>> �\_ 0:0:0:32 sdy � � � �65:128 [active][ready]
>> �\_ 1:0:0:32 sdl � � � �8:176 �[active][ready]
>>
>> Device mapper reports this:
>> # dmsetup ls
>> dm-6_010F � �(253, 6)
>> dm-17_0012 � �(253, 17)
>> dm-13_0103 � �(253, 13)
>> dm-10_0109 � �(253, 10)
>> vg00-app052 � �(253, 3)
>> vg00-xen � �(253, 2)
>> vg00-usr � �(253, 0)
>> vg00-var � �(253, 1)
>> dm-14_0101 � �(253, 14)
>> dm-8_010D � �(253, 8)
>> dm-15_00FF � �(253, 15)
>> dm-11_0107 � �(253, 11)
>> dm-4_0113 � �(253, 4)
>> vg_mds-lvol_mds � �(253, 7)
>> dm-9_010B � �(253, 9)
>> dm-16_00FD � �(253, 16)
>> dm-12_0105 � �(253, 12)
>> dm-5_0111 � �(253, 5)
>>
>>
>> What I do not understand is that surly when I perform a vgscan how will
>> it decide to query only the devices presented from the multipathd, and
>> ignore those presented via the dev/disk/by-id/scsi-nnnnnnnnnn? �Won't it
>> see two vg_mds volumes instead of only those volumes that lie on the
>> multipathed discs, which are the same pshycial discs as the disk/by-id?
>>
>> My plan of action is currently:
>> � � vgchange -a n vg_mds
>> � � vgexport -m /tmp/vg_mds.map mds
>> � � vgexport -f /tmp/vg_mds.pv mds
>> � � vgscan
>> � � vgchange -y a vg_mds
>> � � vgimport vg_mds /*OR instead do it the long way on the next line* �/
>> � � � � vgscan
>> � � � � mkdir /dev/vg_mds
>> � � � � mknod /dev/vg_mds/group c 64 0xNN0000
>> � � � � vgimport -v -s -m /tmp/vg_mds.map /dev/vg_mds
>>
>> I do not see how to tell it to ignore the non-multipathed disc, or has
>> multipathd or LVM have some preference for mutlipath discs over
>> non-multipathed discs, and if so then what is the logic behind the decision?
>>
>> Any help to further my understanding would be gratefully appreciated.
>>
>> Best wishes, S.
>>
>> PS. I am using SLES, but this was the only mailinglist I found for LVM
>> so I subscribed to it. �I think that LVM and multipathd implementations
>> are reasonably similar across Linux distos. Ergo concepts here are
>> applicable to Suse. �The kernel I am using is a xen enabled host (not a
>> guest): 2.6.16.60-0.27-xen #1 SMP.
>>
>>
>
> --
> Simon Loewenthal/Tele2
>
> ******** IMPORTANT NOTICE ********
> Please repect the X-Reply to klunky.co.uk. PGP available 0xD86A5A17.
> S/MIME PKCS12 key available for Lotus Notes: Please ask me for it.
> This e-mail (including any attachments) may contain information that is confidential or otherwise protected from disclosure and it is intended only for the addressees. If you are not the intended recipient, please note that any copying, distribution or other use of information contained in this e-mail (and its attachments) is not allowed. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message (including any attachments) from your system.
> Please note that e-mail messages may contain computer viruses or other defects, may not be accurately replicated on other systems, or may be subject of unauthorized interception or other interference without the knowledge of sender or recipient. Tele2 only send and receive e-mails on the basis that Tele2 is not responsible for any such computer viruses, corruption or other interference or any consequences thereof. �It ought to be obvious that my views do not represent my employer's views.
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2009-12-30 11:52   ` brem belguebli
@ 2009-12-30 12:37     ` Simon Loewenthal/NL/Tele2
  2009-12-30 12:40       ` Simon Loewenthal/NL/Tele2
  2009-12-30 13:00       ` brem belguebli
  2010-01-04 12:54     ` Bryn M. Reeves
  1 sibling, 2 replies; 17+ messages in thread
From: Simon Loewenthal/NL/Tele2 @ 2009-12-30 12:37 UTC (permalink / raw)
  To: LVM general discussion and development

Thank-you Bren for the info., I am unsure how to specify the
preferred_devices using the muttipath:
 Should it be:

preferred_names = [ "^/dev/dm-*/" , "^/dev/cciss/" ]


so that it uses these discs :
/dev/cciss/c0d0p4  (internal disc)
dm-6_010F	(multipathd alias for EMC disc)
dm-17_0012	(multipathd alias for EMC disc)
dm-13_0103	(multipathd alias for EMC disc)
dm-10_0109	(multipathd alias for EMC disc)

The EMC discs are listed under /dev as :
 # ls -l /dev/dm-?
brw-r----- 1 root disk 253, 0 Oct 26 14:44 /dev/dm-0
brw-r----- 1 root disk 253, 1 Oct 26 14:44 /dev/dm-1
brw-r----- 1 root disk 253, 2 Oct 26 14:44 /dev/dm-2
brw-r----- 1 root disk 253, 3 Oct 30 10:16 /dev/dm-3
brw-r----- 1 root disk 253, 4 Dec  4 11:47 /dev/dm-4
brw-r----- 1 root disk 253, 5 Dec  4 11:47 /dev/dm-5
brw-r----- 1 root disk 253, 6 Dec  4 11:47 /dev/dm-6
brw-r----- 1 root disk 253, 7 Oct 26 14:44 /dev/dm-7
brw-r----- 1 root disk 253, 8 Dec  4 11:47 /dev/dm-8
brw-r----- 1 root disk 253, 9 Dec  4 11:47 /dev/dm-9

...but I do not see /dev/dm-6_010F. 


S.



brem belguebli wrote:
> Hi,
>
> see man 5 lvm.conf there is an option called preferred_names which is
> well explained
>
> It'll instruct lvm to use the preferred_names you configured in the
> lvm.conf file if they exist
>
> ie : preferred_names = "/dev/mpath/" will use /dev/mpath/XXX instead
> of /dev/mapper/XXX
>
>
> 2009/12/30 Simon Loewenthal/NL/Tele2 <simon.loewenthal@tele2.com>:
>   
>> I don't think this original Email made it through to the list, but I
>> think I have found an solution:
>>
>> In lvm.conf there is this line,
>> filter = [ "r|/dev/.*/by-path/.*|", "r|/dev/.*/by-id/.*|", "a/.*/" ]
>>
>> If I remove the portion "r|/dev/.*/by-id/.*|", so it is rewritten as,
>> filter = [ "r|/dev/.*/by-path/.*|", "a/.*/" ]
>> ...then it ought to ignore the device,
>> /dev/disk/by-id/scsi-360060480000290300618533030313133
>>
>> Is this correct?
>>
>> S.
>>
>> --
>> Simon Loewenthal/Tele2
>>
>>
>> Simon Loewenthal/NL/Tele2 wrote:
>>     
>>> Dear all,
>>>
>>>     I have a volume group that is currently using discs directly
>>> presented from EMC e.g
>>> /dev/disk/by-id/scsi-360060480000290300618533030313042 .
>>>
>>> An lvdisplay -v shows these PVs:
>>> # vgdisplay -v vg_mds
>>>     Using volume group(s) on command line
>>>     Finding volume group "vg_mds"
>>>   --- Volume group ---
>>>   VG Name               vg_mds
>>>   System ID
>>>   Format                lvm2
>>>   Metadata Areas        12
>>>   Metadata Sequence No  4
>>>   VG Access             read/write
>>>   VG Status             resizable
>>>   MAX LV                0
>>>   Cur LV                1
>>>   Open LV               1
>>>   Max PV                0
>>>   Cur PV                12
>>>   Act PV                12
>>>   VG Size               202.12 GB
>>>   PE Size               32.00 MB
>>>   Total PE              6468
>>>   Alloc PE / Size       6468 / 202.12 GB
>>>   Free  PE / Size       0 / 0
>>>   VG UUID               Wnk1a8-xdVf-RorP-ZxPE-Z3D9-5fp1-2o4hHs
>>>
>>>   --- Logical volume ---
>>>   LV Name                /dev/vg_mds/lvol_mds
>>>   VG Name                vg_mds
>>>   LV UUID                TErCZW-senu-YR3k-I25n-Tqk9-BK2k-3mQY3S
>>>   LV Write Access        read/write
>>>   LV Status              available
>>>   # open                 1
>>>   LV Size                202.12 GB
>>>   Current LE             6468
>>>   Segments               12
>>>   Allocation             inherit
>>>   Read ahead sectors     0
>>>   Block device           253:7
>>>
>>>   --- Physical volumes ---
>>>   PV Name
>>> /dev/disk/by-id/scsi-360060480000290300618533030313133
>>>   PV UUID               255V1X-uMZp-Lod1-3jsa-cCGd-JaNZ-v0dEXn
>>>   PV Status             allocatable
>>>   Total PE / Free PE    539 / 0
>>>
>>>   PV Name
>>> /dev/disk/by-id/scsi-360060480000290300618533030313131
>>>   PV UUID               RU5WZK-G3hY-lXCD-F6Kj-PcJA-DcbE-iV17P7
>>>   PV Status             allocatable
>>>   Total PE / Free PE    539 / 0
>>>
>>>   PV Name
>>> /dev/disk/by-id/scsi-360060480000290300618533030313046
>>>   PV UUID               c3DVym-lzdw-MgS6-acQI-BcUD-UOGq-iG6hSe
>>>   PV Status             allocatable
>>>   Total PE / Free PE    539 / 0
>>>
>>>   PV Name
>>> /dev/disk/by-id/scsi-360060480000290300618533030313044
>>>   PV UUID               d7VD54-KmXZ-t8eX-dvph-9lSp-ym03-Lc62sI
>>>   PV Status             allocatable
>>>   Total PE / Free PE    539 / 0
>>>
>>>   PV Name
>>> /dev/disk/by-id/scsi-360060480000290300618533030313042
>>>   PV UUID               n32oAY-soe3-odYI-SAFQ-yM7v-FRaw-e9hS63
>>>   PV Status             allocatable
>>>   Total PE / Free PE    539 / 0
>>>
>>>   PV Name
>>> /dev/disk/by-id/scsi-360060480000290300618533030313039
>>>   PV UUID               hT2hZ7-XAZr-ZUte-rzLV-kwFX-Jtih-K3OgZe
>>>   PV Status             allocatable
>>>   Total PE / Free PE    539 / 0
>>>
>>>   PV Name
>>> /dev/disk/by-id/scsi-360060480000290300618533030313037
>>>   PV UUID               ut4fEx-R0c2-lA4y-qS3F-SYfp-Chuz-2SrvTo
>>>   PV Status             allocatable
>>>   Total PE / Free PE    539 / 0
>>>
>>>   PV Name
>>> /dev/disk/by-id/scsi-360060480000290300618533030313035
>>>   PV UUID               BMJ8LA-b0L7-aAoK-4WqG-MLdU-s8Y8-xGib2s
>>>   PV Status             allocatable
>>>   Total PE / Free PE    539 / 0
>>>
>>>   PV Name
>>> /dev/disk/by-id/scsi-360060480000290300618533030313033
>>>   PV UUID               uSasZ1-96rT-ngGN-Wfcr-fBNg-ceM0-GaccVU
>>>   PV Status             allocatable
>>>   Total PE / Free PE    539 / 0
>>>
>>>   PV Name
>>> /dev/disk/by-id/scsi-360060480000290300618533030313031
>>>   PV UUID               R15yAf-t1YO-Z0Dx-4n2G-oTyD-Secp-2igMJc
>>>   PV Status             allocatable
>>>   Total PE / Free PE    539 / 0
>>>
>>>   PV Name
>>> /dev/disk/by-id/scsi-360060480000290300618533030304646
>>>   PV UUID               nrhhx1-7AxM-VmVv-sRY5-TLR7-UAEE-wBUIMB
>>>   PV Status             allocatable
>>>   Total PE / Free PE    539 / 0
>>>
>>>   PV Name
>>> /dev/disk/by-id/scsi-360060480000290300618533030304644
>>>   PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
>>>   PV Status             allocatable
>>>   Total PE / Free PE    539 / 0
>>>
>>>
>>> I want to export this volume group and inport it again using
>>> multipathing.  I have configured the multipathing thus,
>>>  # multipath -ll
>>> dm-6_010F (360060480000290300618533030313046) dm-6 EMC,SYMMETRIX
>>> [size=17G][features=0][hwhandler=0]
>>> \_ round-robin 0 [prio=2][active]
>>>  \_ 0:0:0:31 sdx        65:112 [active][ready]
>>>  \_ 1:0:0:31 sdk        8:160  [active][ready]
>>> dm-17_0012 (360060480000290300618533030303132) dm-17 EMC,SYMMETRIX
>>> [size=4.7M][features=0][hwhandler=0]
>>> \_ round-robin 0 [prio=2][active]
>>>  \_ 0:0:0:0  sdn        8:208  [active][ready]
>>>  \_ 1:0:0:0  sda        8:0    [active][ready]
>>> dm-13_0103 (360060480000290300618533030313033) dm-13 EMC,SYMMETRIX
>>> [size=17G][features=0][hwhandler=0]
>>> \_ round-robin 0 [prio=2][active]
>>>  \_ 0:0:0:25 sdr        65:16  [active][ready]
>>>  \_ 1:0:0:25 sde        8:64   [active][ready]
>>> dm-10_0109 (360060480000290300618533030313039) dm-10 EMC,SYMMETRIX
>>> [size=17G][features=0][hwhandler=0]
>>> \_ round-robin 0 [prio=2][active]
>>>  \_ 0:0:0:28 sdu        65:64  [active][ready]
>>>  \_ 1:0:0:28 sdh        8:112  [active][ready]
>>> dm-14_0101 (360060480000290300618533030313031) dm-14 EMC,SYMMETRIX
>>> [size=17G][features=0][hwhandler=0]
>>> \_ round-robin 0 [prio=2][active]
>>>  \_ 0:0:0:24 sdq        65:0   [active][ready]
>>>  \_ 1:0:0:24 sdd        8:48   [active][ready]
>>> dm-8_010D (360060480000290300618533030313044) dm-8 EMC,SYMMETRIX
>>> [size=17G][features=0][hwhandler=0]
>>> \_ round-robin 0 [prio=2][active]
>>>  \_ 0:0:0:30 sdw        65:96  [active][ready]
>>>  \_ 1:0:0:30 sdj        8:144  [active][ready]
>>> dm-15_00FF (360060480000290300618533030304646) dm-15 EMC,SYMMETRIX
>>> [size=17G][features=0][hwhandler=0]
>>> \_ round-robin 0 [prio=2][active]
>>>  \_ 0:0:0:23 sdp        8:240  [active][ready]
>>>  \_ 1:0:0:23 sdc        8:32   [active][ready]
>>> dm-11_0107 (360060480000290300618533030313037) dm-11 EMC,SYMMETRIX
>>> [size=17G][features=0][hwhandler=0]
>>> \_ round-robin 0 [prio=2][active]
>>>  \_ 0:0:0:27 sdt        65:48  [active][ready]
>>>  \_ 1:0:0:27 sdg        8:96   [active][ready]
>>> dm-4_0113 (360060480000290300618533030313133) dm-4 EMC,SYMMETRIX
>>> [size=17G][features=0][hwhandler=0]
>>> \_ round-robin 0 [prio=2][active]
>>>  \_ 0:0:0:33 sdz        65:144 [active][ready]
>>>  \_ 1:0:0:33 sdm        8:192  [active][ready]
>>> dm-9_010B (360060480000290300618533030313042) dm-9 EMC,SYMMETRIX
>>> [size=17G][features=0][hwhandler=0]
>>> \_ round-robin 0 [prio=2][active]
>>>  \_ 0:0:0:29 sdv        65:80  [active][ready]
>>>  \_ 1:0:0:29 sdi        8:128  [active][ready]
>>> dm-16_00FD (360060480000290300618533030304644) dm-16 EMC,SYMMETRIX
>>> [size=17G][features=0][hwhandler=0]
>>> \_ round-robin 0 [prio=2][active]
>>>  \_ 0:0:0:22 sdo        8:224  [active][ready]
>>>  \_ 1:0:0:22 sdb        8:16   [active][ready]
>>> dm-12_0105 (360060480000290300618533030313035) dm-12 EMC,SYMMETRIX
>>> [size=17G][features=0][hwhandler=0]
>>> \_ round-robin 0 [prio=2][active]
>>>  \_ 0:0:0:26 sds        65:32  [active][ready]
>>>  \_ 1:0:0:26 sdf        8:80   [active][ready]
>>> dm-5_0111 (360060480000290300618533030313131) dm-5 EMC,SYMMETRIX
>>> [size=17G][features=0][hwhandler=0]
>>> \_ round-robin 0 [prio=2][active]
>>>  \_ 0:0:0:32 sdy        65:128 [active][ready]
>>>  \_ 1:0:0:32 sdl        8:176  [active][ready]
>>>
>>> Device mapper reports this:
>>> # dmsetup ls
>>> dm-6_010F    (253, 6)
>>> dm-17_0012    (253, 17)
>>> dm-13_0103    (253, 13)
>>> dm-10_0109    (253, 10)
>>> vg00-app052    (253, 3)
>>> vg00-xen    (253, 2)
>>> vg00-usr    (253, 0)
>>> vg00-var    (253, 1)
>>> dm-14_0101    (253, 14)
>>> dm-8_010D    (253, 8)
>>> dm-15_00FF    (253, 15)
>>> dm-11_0107    (253, 11)
>>> dm-4_0113    (253, 4)
>>> vg_mds-lvol_mds    (253, 7)
>>> dm-9_010B    (253, 9)
>>> dm-16_00FD    (253, 16)
>>> dm-12_0105    (253, 12)
>>> dm-5_0111    (253, 5)
>>>
>>>
>>> What I do not understand is that surly when I perform a vgscan how will
>>> it decide to query only the devices presented from the multipathd, and
>>> ignore those presented via the dev/disk/by-id/scsi-nnnnnnnnnn?  Won't it
>>> see two vg_mds volumes instead of only those volumes that lie on the
>>> multipathed discs, which are the same pshycial discs as the disk/by-id?
>>>
>>> My plan of action is currently:
>>>     vgchange -a n vg_mds
>>>     vgexport -m /tmp/vg_mds.map mds
>>>     vgexport -f /tmp/vg_mds.pv mds
>>>     vgscan
>>>     vgchange -y a vg_mds
>>>     vgimport vg_mds /*OR instead do it the long way on the next line*  /
>>>         vgscan
>>>         mkdir /dev/vg_mds
>>>         mknod /dev/vg_mds/group c 64 0xNN0000
>>>         vgimport -v -s -m /tmp/vg_mds.map /dev/vg_mds
>>>
>>> I do not see how to tell it to ignore the non-multipathed disc, or has
>>> multipathd or LVM have some preference for mutlipath discs over
>>> non-multipathed discs, and if so then what is the logic behind the decision?
>>>
>>> Any help to further my understanding would be gratefully appreciated.
>>>
>>> Best wishes, S.
>>>
>>> PS. I am using SLES, but this was the only mailinglist I found for LVM
>>> so I subscribed to it.  I think that LVM and multipathd implementations
>>> are reasonably similar across Linux distos. Ergo concepts here are
>>> applicable to Suse.  The kernel I am using is a xen enabled host (not a
>>> guest): 2.6.16.60-0.27-xen #1 SMP.
>>>
>>>
>>>       
>> --
>> Simon Loewenthal/Tele2
>>
>> ******** IMPORTANT NOTICE ********
>> Please repect the X-Reply to klunky.co.uk. PGP available 0xD86A5A17.
>> S/MIME PKCS12 key available for Lotus Notes: Please ask me for it.
>> This e-mail (including any attachments) may contain information that is confidential or otherwise protected from disclosure and it is intended only for the addressees. If you are not the intended recipient, please note that any copying, distribution or other use of information contained in this e-mail (and its attachments) is not allowed. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message (including any attachments) from your system.
>> Please note that e-mail messages may contain computer viruses or other defects, may not be accurately replicated on other systems, or may be subject of unauthorized interception or other interference without the knowledge of sender or recipient. Tele2 only send and receive e-mails on the basis that Tele2 is not responsible for any such computer viruses, corruption or other interference or any consequences thereof.  It ought to be obvious that my views do not represent my employer's views.
>>
>> _______________________________________________
>> linux-lvm mailing list
>> linux-lvm@redhat.com
>> https://www.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>
>>     
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>   

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2009-12-30 12:37     ` Simon Loewenthal/NL/Tele2
@ 2009-12-30 12:40       ` Simon Loewenthal/NL/Tele2
  2009-12-30 13:00       ` brem belguebli
  1 sibling, 0 replies; 17+ messages in thread
From: Simon Loewenthal/NL/Tele2 @ 2009-12-30 12:40 UTC (permalink / raw)
  To: LVM general discussion and development

Sorry, no, I think it should have been,

    preferred_names = [ "^/dev/mapper/" , "^/dev/cciss/" ]

for these in /dev/mapper:

 # ls -l /dev/mapper
total 0
lrwxrwxrwx 1 root root      16 Oct 26 14:44 control -> ../device-mapper
brw------- 1 root root 253, 10 Dec  4 11:47 dm-10_0109
brw------- 1 root root 253, 11 Dec  4 11:47 dm-11_0107
brw------- 1 root root 253, 12 Dec  4 11:47 dm-12_0105
brw------- 1 root root 253, 13 Dec  4 11:47 dm-13_0103
brw------- 1 root root 253, 14 Dec  4 11:47 dm-14_0101
brw------- 1 root root 253, 15 Dec  4 11:47 dm-15_00FF
brw------- 1 root root 253, 16 Dec  4 11:47 dm-16_00FD
brw------- 1 root root 253, 17 Dec  4 11:47 dm-17_0012
brw------- 1 root root 253,  4 Dec  4 11:47 dm-4_0113
brw------- 1 root root 253,  5 Dec  4 11:47 dm-5_0111
brw------- 1 root root 253,  6 Dec  4 11:47 dm-6_010F
brw------- 1 root root 253,  8 Dec  4 11:47 dm-8_010D
brw------- 1 root root 253,  9 Dec  4 11:47 dm-9_010B
brw------- 1 root root 253,  3 Oct 30 10:17 vg00-app052
brw------- 1 root root 253,  0 Oct 26 14:45 vg00-usr
brw------- 1 root root 253,  1 Oct 26 14:45 vg00-var
brw------- 1 root root 253,  2 Oct 26 14:45 vg00-xen
brw------- 1 root root 253,  7 Oct 26 14:44 vg_mds-lvol_mds


Simon Loewenthal/NL/Tele2 wrote:
> Thank-you Bren for the info., I am unsure how to specify the
> preferred_devices using the muttipath:
>  Should it be:
>
> preferred_names = [ "^/dev/dm-*/" , "^/dev/cciss/" ]
>
>
> so that it uses these discs :
> /dev/cciss/c0d0p4  (internal disc)
> dm-6_010F	(multipathd alias for EMC disc)
> dm-17_0012	(multipathd alias for EMC disc)
> dm-13_0103	(multipathd alias for EMC disc)
> dm-10_0109	(multipathd alias for EMC disc)
>
> The EMC discs are listed under /dev as :
>  # ls -l /dev/dm-?
> brw-r----- 1 root disk 253, 0 Oct 26 14:44 /dev/dm-0
> brw-r----- 1 root disk 253, 1 Oct 26 14:44 /dev/dm-1
> brw-r----- 1 root disk 253, 2 Oct 26 14:44 /dev/dm-2
> brw-r----- 1 root disk 253, 3 Oct 30 10:16 /dev/dm-3
> brw-r----- 1 root disk 253, 4 Dec  4 11:47 /dev/dm-4
> brw-r----- 1 root disk 253, 5 Dec  4 11:47 /dev/dm-5
> brw-r----- 1 root disk 253, 6 Dec  4 11:47 /dev/dm-6
> brw-r----- 1 root disk 253, 7 Oct 26 14:44 /dev/dm-7
> brw-r----- 1 root disk 253, 8 Dec  4 11:47 /dev/dm-8
> brw-r----- 1 root disk 253, 9 Dec  4 11:47 /dev/dm-9
>
> ...but I do not see /dev/dm-6_010F. 
>
>
> S.
>
>
>
> brem belguebli wrote:
>   
>> Hi,
>>
>> see man 5 lvm.conf there is an option called preferred_names which is
>> well explained
>>
>> It'll instruct lvm to use the preferred_names you configured in the
>> lvm.conf file if they exist
>>
>> ie : preferred_names = "/dev/mpath/" will use /dev/mpath/XXX instead
>> of /dev/mapper/XXX
>>
>>
>> 2009/12/30 Simon Loewenthal/NL/Tele2 <simon.loewenthal@tele2.com>:
>>   
>>     
>>> I don't think this original Email made it through to the list, but I
>>> think I have found an solution:
>>>
>>> In lvm.conf there is this line,
>>> filter = [ "r|/dev/.*/by-path/.*|", "r|/dev/.*/by-id/.*|", "a/.*/" ]
>>>
>>> If I remove the portion "r|/dev/.*/by-id/.*|", so it is rewritten as,
>>> filter = [ "r|/dev/.*/by-path/.*|", "a/.*/" ]
>>> ...then it ought to ignore the device,
>>> /dev/disk/by-id/scsi-360060480000290300618533030313133
>>>
>>> Is this correct?
>>>
>>> S.
>>>
>>> --
>>> Simon Loewenthal/Tele2
>>>
>>>
>>> Simon Loewenthal/NL/Tele2 wrote:
>>>     
>>>       
>>>> Dear all,
>>>>
>>>>     I have a volume group that is currently using discs directly
>>>> presented from EMC e.g
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313042 .
>>>>
>>>> An lvdisplay -v shows these PVs:
>>>> # vgdisplay -v vg_mds
>>>>     Using volume group(s) on command line
>>>>     Finding volume group "vg_mds"
>>>>   --- Volume group ---
>>>>   VG Name               vg_mds
>>>>   System ID
>>>>   Format                lvm2
>>>>   Metadata Areas        12
>>>>   Metadata Sequence No  4
>>>>   VG Access             read/write
>>>>   VG Status             resizable
>>>>   MAX LV                0
>>>>   Cur LV                1
>>>>   Open LV               1
>>>>   Max PV                0
>>>>   Cur PV                12
>>>>   Act PV                12
>>>>   VG Size               202.12 GB
>>>>   PE Size               32.00 MB
>>>>   Total PE              6468
>>>>   Alloc PE / Size       6468 / 202.12 GB
>>>>   Free  PE / Size       0 / 0
>>>>   VG UUID               Wnk1a8-xdVf-RorP-ZxPE-Z3D9-5fp1-2o4hHs
>>>>
>>>>   --- Logical volume ---
>>>>   LV Name                /dev/vg_mds/lvol_mds
>>>>   VG Name                vg_mds
>>>>   LV UUID                TErCZW-senu-YR3k-I25n-Tqk9-BK2k-3mQY3S
>>>>   LV Write Access        read/write
>>>>   LV Status              available
>>>>   # open                 1
>>>>   LV Size                202.12 GB
>>>>   Current LE             6468
>>>>   Segments               12
>>>>   Allocation             inherit
>>>>   Read ahead sectors     0
>>>>   Block device           253:7
>>>>
>>>>   --- Physical volumes ---
>>>>   PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313133
>>>>   PV UUID               255V1X-uMZp-Lod1-3jsa-cCGd-JaNZ-v0dEXn
>>>>   PV Status             allocatable
>>>>   Total PE / Free PE    539 / 0
>>>>
>>>>   PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313131
>>>>   PV UUID               RU5WZK-G3hY-lXCD-F6Kj-PcJA-DcbE-iV17P7
>>>>   PV Status             allocatable
>>>>   Total PE / Free PE    539 / 0
>>>>
>>>>   PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313046
>>>>   PV UUID               c3DVym-lzdw-MgS6-acQI-BcUD-UOGq-iG6hSe
>>>>   PV Status             allocatable
>>>>   Total PE / Free PE    539 / 0
>>>>
>>>>   PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313044
>>>>   PV UUID               d7VD54-KmXZ-t8eX-dvph-9lSp-ym03-Lc62sI
>>>>   PV Status             allocatable
>>>>   Total PE / Free PE    539 / 0
>>>>
>>>>   PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313042
>>>>   PV UUID               n32oAY-soe3-odYI-SAFQ-yM7v-FRaw-e9hS63
>>>>   PV Status             allocatable
>>>>   Total PE / Free PE    539 / 0
>>>>
>>>>   PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313039
>>>>   PV UUID               hT2hZ7-XAZr-ZUte-rzLV-kwFX-Jtih-K3OgZe
>>>>   PV Status             allocatable
>>>>   Total PE / Free PE    539 / 0
>>>>
>>>>   PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313037
>>>>   PV UUID               ut4fEx-R0c2-lA4y-qS3F-SYfp-Chuz-2SrvTo
>>>>   PV Status             allocatable
>>>>   Total PE / Free PE    539 / 0
>>>>
>>>>   PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313035
>>>>   PV UUID               BMJ8LA-b0L7-aAoK-4WqG-MLdU-s8Y8-xGib2s
>>>>   PV Status             allocatable
>>>>   Total PE / Free PE    539 / 0
>>>>
>>>>   PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313033
>>>>   PV UUID               uSasZ1-96rT-ngGN-Wfcr-fBNg-ceM0-GaccVU
>>>>   PV Status             allocatable
>>>>   Total PE / Free PE    539 / 0
>>>>
>>>>   PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313031
>>>>   PV UUID               R15yAf-t1YO-Z0Dx-4n2G-oTyD-Secp-2igMJc
>>>>   PV Status             allocatable
>>>>   Total PE / Free PE    539 / 0
>>>>
>>>>   PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030304646
>>>>   PV UUID               nrhhx1-7AxM-VmVv-sRY5-TLR7-UAEE-wBUIMB
>>>>   PV Status             allocatable
>>>>   Total PE / Free PE    539 / 0
>>>>
>>>>   PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030304644
>>>>   PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
>>>>   PV Status             allocatable
>>>>   Total PE / Free PE    539 / 0
>>>>
>>>>
>>>> I want to export this volume group and inport it again using
>>>> multipathing.  I have configured the multipathing thus,
>>>>  # multipath -ll
>>>> dm-6_010F (360060480000290300618533030313046) dm-6 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>>  \_ 0:0:0:31 sdx        65:112 [active][ready]
>>>>  \_ 1:0:0:31 sdk        8:160  [active][ready]
>>>> dm-17_0012 (360060480000290300618533030303132) dm-17 EMC,SYMMETRIX
>>>> [size=4.7M][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>>  \_ 0:0:0:0  sdn        8:208  [active][ready]
>>>>  \_ 1:0:0:0  sda        8:0    [active][ready]
>>>> dm-13_0103 (360060480000290300618533030313033) dm-13 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>>  \_ 0:0:0:25 sdr        65:16  [active][ready]
>>>>  \_ 1:0:0:25 sde        8:64   [active][ready]
>>>> dm-10_0109 (360060480000290300618533030313039) dm-10 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>>  \_ 0:0:0:28 sdu        65:64  [active][ready]
>>>>  \_ 1:0:0:28 sdh        8:112  [active][ready]
>>>> dm-14_0101 (360060480000290300618533030313031) dm-14 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>>  \_ 0:0:0:24 sdq        65:0   [active][ready]
>>>>  \_ 1:0:0:24 sdd        8:48   [active][ready]
>>>> dm-8_010D (360060480000290300618533030313044) dm-8 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>>  \_ 0:0:0:30 sdw        65:96  [active][ready]
>>>>  \_ 1:0:0:30 sdj        8:144  [active][ready]
>>>> dm-15_00FF (360060480000290300618533030304646) dm-15 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>>  \_ 0:0:0:23 sdp        8:240  [active][ready]
>>>>  \_ 1:0:0:23 sdc        8:32   [active][ready]
>>>> dm-11_0107 (360060480000290300618533030313037) dm-11 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>>  \_ 0:0:0:27 sdt        65:48  [active][ready]
>>>>  \_ 1:0:0:27 sdg        8:96   [active][ready]
>>>> dm-4_0113 (360060480000290300618533030313133) dm-4 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>>  \_ 0:0:0:33 sdz        65:144 [active][ready]
>>>>  \_ 1:0:0:33 sdm        8:192  [active][ready]
>>>> dm-9_010B (360060480000290300618533030313042) dm-9 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>>  \_ 0:0:0:29 sdv        65:80  [active][ready]
>>>>  \_ 1:0:0:29 sdi        8:128  [active][ready]
>>>> dm-16_00FD (360060480000290300618533030304644) dm-16 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>>  \_ 0:0:0:22 sdo        8:224  [active][ready]
>>>>  \_ 1:0:0:22 sdb        8:16   [active][ready]
>>>> dm-12_0105 (360060480000290300618533030313035) dm-12 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>>  \_ 0:0:0:26 sds        65:32  [active][ready]
>>>>  \_ 1:0:0:26 sdf        8:80   [active][ready]
>>>> dm-5_0111 (360060480000290300618533030313131) dm-5 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>>  \_ 0:0:0:32 sdy        65:128 [active][ready]
>>>>  \_ 1:0:0:32 sdl        8:176  [active][ready]
>>>>
>>>> Device mapper reports this:
>>>> # dmsetup ls
>>>> dm-6_010F    (253, 6)
>>>> dm-17_0012    (253, 17)
>>>> dm-13_0103    (253, 13)
>>>> dm-10_0109    (253, 10)
>>>> vg00-app052    (253, 3)
>>>> vg00-xen    (253, 2)
>>>> vg00-usr    (253, 0)
>>>> vg00-var    (253, 1)
>>>> dm-14_0101    (253, 14)
>>>> dm-8_010D    (253, 8)
>>>> dm-15_00FF    (253, 15)
>>>> dm-11_0107    (253, 11)
>>>> dm-4_0113    (253, 4)
>>>> vg_mds-lvol_mds    (253, 7)
>>>> dm-9_010B    (253, 9)
>>>> dm-16_00FD    (253, 16)
>>>> dm-12_0105    (253, 12)
>>>> dm-5_0111    (253, 5)
>>>>
>>>>
>>>> What I do not understand is that surly when I perform a vgscan how will
>>>> it decide to query only the devices presented from the multipathd, and
>>>> ignore those presented via the dev/disk/by-id/scsi-nnnnnnnnnn?  Won't it
>>>> see two vg_mds volumes instead of only those volumes that lie on the
>>>> multipathed discs, which are the same pshycial discs as the disk/by-id?
>>>>
>>>> My plan of action is currently:
>>>>     vgchange -a n vg_mds
>>>>     vgexport -m /tmp/vg_mds.map mds
>>>>     vgexport -f /tmp/vg_mds.pv mds
>>>>     vgscan
>>>>     vgchange -y a vg_mds
>>>>     vgimport vg_mds /*OR instead do it the long way on the next line*  /
>>>>         vgscan
>>>>         mkdir /dev/vg_mds
>>>>         mknod /dev/vg_mds/group c 64 0xNN0000
>>>>         vgimport -v -s -m /tmp/vg_mds.map /dev/vg_mds
>>>>
>>>> I do not see how to tell it to ignore the non-multipathed disc, or has
>>>> multipathd or LVM have some preference for mutlipath discs over
>>>> non-multipathed discs, and if so then what is the logic behind the decision?
>>>>
>>>> Any help to further my understanding would be gratefully appreciated.
>>>>
>>>> Best wishes, S.
>>>>
>>>> PS. I am using SLES, but this was the only mailinglist I found for LVM
>>>> so I subscribed to it.  I think that LVM and multipathd implementations
>>>> are reasonably similar across Linux distos. Ergo concepts here are
>>>> applicable to Suse.  The kernel I am using is a xen enabled host (not a
>>>> guest): 2.6.16.60-0.27-xen #1 SMP.
>>>>
>>>>
>>>>       
>>>>         
>>> --
>>> Simon Loewenthal/Tele2
>>>
>>> ******** IMPORTANT NOTICE ********
>>> Please repect the X-Reply to klunky.co.uk. PGP available 0xD86A5A17.
>>> S/MIME PKCS12 key available for Lotus Notes: Please ask me for it.
>>> This e-mail (including any attachments) may contain information that is confidential or otherwise protected from disclosure and it is intended only for the addressees. If you are not the intended recipient, please note that any copying, distribution or other use of information contained in this e-mail (and its attachments) is not allowed. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message (including any attachments) from your system.
>>> Please note that e-mail messages may contain computer viruses or other defects, may not be accurately replicated on other systems, or may be subject of unauthorized interception or other interference without the knowledge of sender or recipient. Tele2 only send and receive e-mails on the basis that Tele2 is not responsible for any such computer viruses, corruption or other interference or any consequences thereof.  It ought to be obvious that my views do not represent my employer's views.
>>>
>>> _______________________________________________
>>> linux-lvm mailing list
>>> linux-lvm@redhat.com
>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>
>>>     
>>>       
>> _______________________________________________
>> linux-lvm mailing list
>> linux-lvm@redhat.com
>> https://www.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>   
>>     
>
>   

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2009-12-30 12:37     ` Simon Loewenthal/NL/Tele2
  2009-12-30 12:40       ` Simon Loewenthal/NL/Tele2
@ 2009-12-30 13:00       ` brem belguebli
  2009-12-30 13:45         ` Simon Loewenthal/NL/Tele2
  1 sibling, 1 reply; 17+ messages in thread
From: brem belguebli @ 2009-12-30 13:00 UTC (permalink / raw)
  To: LVM general discussion and development

What you have to be aware of is that /dev/dm names are volatile and
can change across reboots as are /dev/sd names, never use them
directly.

If you are using device-mapper-multipath (not emcpowerpath) there is a
"user_friendly_names" boolean setting in /etc/multipath.conf that
would give you names such as /dev/mpath/mpath0 is set to yes.

If set to no, it would give you names such as /dev/mpath/UUID.

Both namings are persistent (stable across reboots) as multipath will
base its binding on the disk UUID.

see man multipath.conf to have full options listing.

It allows you also to give custom names to devices by using the alias
setting in multipath.conf.

The filter you applied (your previous email) just prevents "r/..." LVM
to check and so activate the device names that you rejected.

Hope this'll help

2009/12/30 Simon Loewenthal/NL/Tele2 <simon.loewenthal@klunky.co.uk>:
> Thank-you Bren for the info., I am unsure how to specify the
> preferred_devices using the muttipath:
> �Should it be:
>
> preferred_names = [ "^/dev/dm-*/" , "^/dev/cciss/" ]
>
>
> so that it uses these discs :
> /dev/cciss/c0d0p4 �(internal disc)
> dm-6_010F � � � (multipathd alias for EMC disc)
> dm-17_0012 � � �(multipathd alias for EMC disc)
> dm-13_0103 � � �(multipathd alias for EMC disc)
> dm-10_0109 � � �(multipathd alias for EMC disc)
>
> The EMC discs are listed under /dev as :
> �# ls -l /dev/dm-?
> brw-r----- 1 root disk 253, 0 Oct 26 14:44 /dev/dm-0
> brw-r----- 1 root disk 253, 1 Oct 26 14:44 /dev/dm-1
> brw-r----- 1 root disk 253, 2 Oct 26 14:44 /dev/dm-2
> brw-r----- 1 root disk 253, 3 Oct 30 10:16 /dev/dm-3
> brw-r----- 1 root disk 253, 4 Dec �4 11:47 /dev/dm-4
> brw-r----- 1 root disk 253, 5 Dec �4 11:47 /dev/dm-5
> brw-r----- 1 root disk 253, 6 Dec �4 11:47 /dev/dm-6
> brw-r----- 1 root disk 253, 7 Oct 26 14:44 /dev/dm-7
> brw-r----- 1 root disk 253, 8 Dec �4 11:47 /dev/dm-8
> brw-r----- 1 root disk 253, 9 Dec �4 11:47 /dev/dm-9
>
> ...but I do not see /dev/dm-6_010F.
>
>
> S.
>
>
>
> brem belguebli wrote:
>> Hi,
>>
>> see man 5 lvm.conf there is an option called preferred_names which is
>> well explained
>>
>> It'll instruct lvm to use the preferred_names you configured in the
>> lvm.conf file if they exist
>>
>> ie : preferred_names = "/dev/mpath/" will use /dev/mpath/XXX instead
>> of /dev/mapper/XXX
>>
>>
>> 2009/12/30 Simon Loewenthal/NL/Tele2 <simon.loewenthal@tele2.com>:
>>
>>> I don't think this original Email made it through to the list, but I
>>> think I have found an solution:
>>>
>>> In lvm.conf there is this line,
>>> filter = [ "r|/dev/.*/by-path/.*|", "r|/dev/.*/by-id/.*|", "a/.*/" ]
>>>
>>> If I remove the portion "r|/dev/.*/by-id/.*|", so it is rewritten as,
>>> filter = [ "r|/dev/.*/by-path/.*|", "a/.*/" ]
>>> ...then it ought to ignore the device,
>>> /dev/disk/by-id/scsi-360060480000290300618533030313133
>>>
>>> Is this correct?
>>>
>>> S.
>>>
>>> --
>>> Simon Loewenthal/Tele2
>>>
>>>
>>> Simon Loewenthal/NL/Tele2 wrote:
>>>
>>>> Dear all,
>>>>
>>>> � � I have a volume group that is currently using discs directly
>>>> presented from EMC e.g
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313042 .
>>>>
>>>> An lvdisplay -v shows these PVs:
>>>> # vgdisplay -v vg_mds
>>>> � � Using volume group(s) on command line
>>>> � � Finding volume group "vg_mds"
>>>> � --- Volume group ---
>>>> � VG Name � � � � � � � vg_mds
>>>> � System ID
>>>> � Format � � � � � � � �lvm2
>>>> � Metadata Areas � � � �12
>>>> � Metadata Sequence No �4
>>>> � VG Access � � � � � � read/write
>>>> � VG Status � � � � � � resizable
>>>> � MAX LV � � � � � � � �0
>>>> � Cur LV � � � � � � � �1
>>>> � Open LV � � � � � � � 1
>>>> � Max PV � � � � � � � �0
>>>> � Cur PV � � � � � � � �12
>>>> � Act PV � � � � � � � �12
>>>> � VG Size � � � � � � � 202.12 GB
>>>> � PE Size � � � � � � � 32.00 MB
>>>> � Total PE � � � � � � �6468
>>>> � Alloc PE / Size � � � 6468 / 202.12 GB
>>>> � Free �PE / Size � � � 0 / 0
>>>> � VG UUID � � � � � � � Wnk1a8-xdVf-RorP-ZxPE-Z3D9-5fp1-2o4hHs
>>>>
>>>> � --- Logical volume ---
>>>> � LV Name � � � � � � � �/dev/vg_mds/lvol_mds
>>>> � VG Name � � � � � � � �vg_mds
>>>> � LV UUID � � � � � � � �TErCZW-senu-YR3k-I25n-Tqk9-BK2k-3mQY3S
>>>> � LV Write Access � � � �read/write
>>>> � LV Status � � � � � � �available
>>>> � # open � � � � � � � � 1
>>>> � LV Size � � � � � � � �202.12 GB
>>>> � Current LE � � � � � � 6468
>>>> � Segments � � � � � � � 12
>>>> � Allocation � � � � � � inherit
>>>> � Read ahead sectors � � 0
>>>> � Block device � � � � � 253:7
>>>>
>>>> � --- Physical volumes ---
>>>> � PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313133
>>>> � PV UUID � � � � � � � 255V1X-uMZp-Lod1-3jsa-cCGd-JaNZ-v0dEXn
>>>> � PV Status � � � � � � allocatable
>>>> � Total PE / Free PE � �539 / 0
>>>>
>>>> � PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313131
>>>> � PV UUID � � � � � � � RU5WZK-G3hY-lXCD-F6Kj-PcJA-DcbE-iV17P7
>>>> � PV Status � � � � � � allocatable
>>>> � Total PE / Free PE � �539 / 0
>>>>
>>>> � PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313046
>>>> � PV UUID � � � � � � � c3DVym-lzdw-MgS6-acQI-BcUD-UOGq-iG6hSe
>>>> � PV Status � � � � � � allocatable
>>>> � Total PE / Free PE � �539 / 0
>>>>
>>>> � PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313044
>>>> � PV UUID � � � � � � � d7VD54-KmXZ-t8eX-dvph-9lSp-ym03-Lc62sI
>>>> � PV Status � � � � � � allocatable
>>>> � Total PE / Free PE � �539 / 0
>>>>
>>>> � PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313042
>>>> � PV UUID � � � � � � � n32oAY-soe3-odYI-SAFQ-yM7v-FRaw-e9hS63
>>>> � PV Status � � � � � � allocatable
>>>> � Total PE / Free PE � �539 / 0
>>>>
>>>> � PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313039
>>>> � PV UUID � � � � � � � hT2hZ7-XAZr-ZUte-rzLV-kwFX-Jtih-K3OgZe
>>>> � PV Status � � � � � � allocatable
>>>> � Total PE / Free PE � �539 / 0
>>>>
>>>> � PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313037
>>>> � PV UUID � � � � � � � ut4fEx-R0c2-lA4y-qS3F-SYfp-Chuz-2SrvTo
>>>> � PV Status � � � � � � allocatable
>>>> � Total PE / Free PE � �539 / 0
>>>>
>>>> � PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313035
>>>> � PV UUID � � � � � � � BMJ8LA-b0L7-aAoK-4WqG-MLdU-s8Y8-xGib2s
>>>> � PV Status � � � � � � allocatable
>>>> � Total PE / Free PE � �539 / 0
>>>>
>>>> � PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313033
>>>> � PV UUID � � � � � � � uSasZ1-96rT-ngGN-Wfcr-fBNg-ceM0-GaccVU
>>>> � PV Status � � � � � � allocatable
>>>> � Total PE / Free PE � �539 / 0
>>>>
>>>> � PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313031
>>>> � PV UUID � � � � � � � R15yAf-t1YO-Z0Dx-4n2G-oTyD-Secp-2igMJc
>>>> � PV Status � � � � � � allocatable
>>>> � Total PE / Free PE � �539 / 0
>>>>
>>>> � PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030304646
>>>> � PV UUID � � � � � � � nrhhx1-7AxM-VmVv-sRY5-TLR7-UAEE-wBUIMB
>>>> � PV Status � � � � � � allocatable
>>>> � Total PE / Free PE � �539 / 0
>>>>
>>>> � PV Name
>>>> /dev/disk/by-id/scsi-360060480000290300618533030304644
>>>> � PV UUID � � � � � � � ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
>>>> � PV Status � � � � � � allocatable
>>>> � Total PE / Free PE � �539 / 0
>>>>
>>>>
>>>> I want to export this volume group and inport it again using
>>>> multipathing. �I have configured the multipathing thus,
>>>> �# multipath -ll
>>>> dm-6_010F (360060480000290300618533030313046) dm-6 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>> �\_ 0:0:0:31 sdx � � � �65:112 [active][ready]
>>>> �\_ 1:0:0:31 sdk � � � �8:160 �[active][ready]
>>>> dm-17_0012 (360060480000290300618533030303132) dm-17 EMC,SYMMETRIX
>>>> [size=4.7M][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>> �\_ 0:0:0:0 �sdn � � � �8:208 �[active][ready]
>>>> �\_ 1:0:0:0 �sda � � � �8:0 � �[active][ready]
>>>> dm-13_0103 (360060480000290300618533030313033) dm-13 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>> �\_ 0:0:0:25 sdr � � � �65:16 �[active][ready]
>>>> �\_ 1:0:0:25 sde � � � �8:64 � [active][ready]
>>>> dm-10_0109 (360060480000290300618533030313039) dm-10 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>> �\_ 0:0:0:28 sdu � � � �65:64 �[active][ready]
>>>> �\_ 1:0:0:28 sdh � � � �8:112 �[active][ready]
>>>> dm-14_0101 (360060480000290300618533030313031) dm-14 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>> �\_ 0:0:0:24 sdq � � � �65:0 � [active][ready]
>>>> �\_ 1:0:0:24 sdd � � � �8:48 � [active][ready]
>>>> dm-8_010D (360060480000290300618533030313044) dm-8 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>> �\_ 0:0:0:30 sdw � � � �65:96 �[active][ready]
>>>> �\_ 1:0:0:30 sdj � � � �8:144 �[active][ready]
>>>> dm-15_00FF (360060480000290300618533030304646) dm-15 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>> �\_ 0:0:0:23 sdp � � � �8:240 �[active][ready]
>>>> �\_ 1:0:0:23 sdc � � � �8:32 � [active][ready]
>>>> dm-11_0107 (360060480000290300618533030313037) dm-11 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>> �\_ 0:0:0:27 sdt � � � �65:48 �[active][ready]
>>>> �\_ 1:0:0:27 sdg � � � �8:96 � [active][ready]
>>>> dm-4_0113 (360060480000290300618533030313133) dm-4 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>> �\_ 0:0:0:33 sdz � � � �65:144 [active][ready]
>>>> �\_ 1:0:0:33 sdm � � � �8:192 �[active][ready]
>>>> dm-9_010B (360060480000290300618533030313042) dm-9 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>> �\_ 0:0:0:29 sdv � � � �65:80 �[active][ready]
>>>> �\_ 1:0:0:29 sdi � � � �8:128 �[active][ready]
>>>> dm-16_00FD (360060480000290300618533030304644) dm-16 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>> �\_ 0:0:0:22 sdo � � � �8:224 �[active][ready]
>>>> �\_ 1:0:0:22 sdb � � � �8:16 � [active][ready]
>>>> dm-12_0105 (360060480000290300618533030313035) dm-12 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>> �\_ 0:0:0:26 sds � � � �65:32 �[active][ready]
>>>> �\_ 1:0:0:26 sdf � � � �8:80 � [active][ready]
>>>> dm-5_0111 (360060480000290300618533030313131) dm-5 EMC,SYMMETRIX
>>>> [size=17G][features=0][hwhandler=0]
>>>> \_ round-robin 0 [prio=2][active]
>>>> �\_ 0:0:0:32 sdy � � � �65:128 [active][ready]
>>>> �\_ 1:0:0:32 sdl � � � �8:176 �[active][ready]
>>>>
>>>> Device mapper reports this:
>>>> # dmsetup ls
>>>> dm-6_010F � �(253, 6)
>>>> dm-17_0012 � �(253, 17)
>>>> dm-13_0103 � �(253, 13)
>>>> dm-10_0109 � �(253, 10)
>>>> vg00-app052 � �(253, 3)
>>>> vg00-xen � �(253, 2)
>>>> vg00-usr � �(253, 0)
>>>> vg00-var � �(253, 1)
>>>> dm-14_0101 � �(253, 14)
>>>> dm-8_010D � �(253, 8)
>>>> dm-15_00FF � �(253, 15)
>>>> dm-11_0107 � �(253, 11)
>>>> dm-4_0113 � �(253, 4)
>>>> vg_mds-lvol_mds � �(253, 7)
>>>> dm-9_010B � �(253, 9)
>>>> dm-16_00FD � �(253, 16)
>>>> dm-12_0105 � �(253, 12)
>>>> dm-5_0111 � �(253, 5)
>>>>
>>>>
>>>> What I do not understand is that surly when I perform a vgscan how will
>>>> it decide to query only the devices presented from the multipathd, and
>>>> ignore those presented via the dev/disk/by-id/scsi-nnnnnnnnnn? �Won't it
>>>> see two vg_mds volumes instead of only those volumes that lie on the
>>>> multipathed discs, which are the same pshycial discs as the disk/by-id?
>>>>
>>>> My plan of action is currently:
>>>> � � vgchange -a n vg_mds
>>>> � � vgexport -m /tmp/vg_mds.map mds
>>>> � � vgexport -f /tmp/vg_mds.pv mds
>>>> � � vgscan
>>>> � � vgchange -y a vg_mds
>>>> � � vgimport vg_mds /*OR instead do it the long way on the next line* �/
>>>> � � � � vgscan
>>>> � � � � mkdir /dev/vg_mds
>>>> � � � � mknod /dev/vg_mds/group c 64 0xNN0000
>>>> � � � � vgimport -v -s -m /tmp/vg_mds.map /dev/vg_mds
>>>>
>>>> I do not see how to tell it to ignore the non-multipathed disc, or has
>>>> multipathd or LVM have some preference for mutlipath discs over
>>>> non-multipathed discs, and if so then what is the logic behind the decision?
>>>>
>>>> Any help to further my understanding would be gratefully appreciated.
>>>>
>>>> Best wishes, S.
>>>>
>>>> PS. I am using SLES, but this was the only mailinglist I found for LVM
>>>> so I subscribed to it. �I think that LVM and multipathd implementations
>>>> are reasonably similar across Linux distos. Ergo concepts here are
>>>> applicable to Suse. �The kernel I am using is a xen enabled host (not a
>>>> guest): 2.6.16.60-0.27-xen #1 SMP.
>>>>
>>>>
>>>>
>>> --
>>> Simon Loewenthal/Tele2
>>>
>>> ******** IMPORTANT NOTICE ********
>>> Please repect the X-Reply to klunky.co.uk. PGP available 0xD86A5A17.
>>> S/MIME PKCS12 key available for Lotus Notes: Please ask me for it.
>>> This e-mail (including any attachments) may contain information that is confidential or otherwise protected from disclosure and it is intended only for the addressees. If you are not the intended recipient, please note that any copying, distribution or other use of information contained in this e-mail (and its attachments) is not allowed. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message (including any attachments) from your system.
>>> Please note that e-mail messages may contain computer viruses or other defects, may not be accurately replicated on other systems, or may be subject of unauthorized interception or other interference without the knowledge of sender or recipient. Tele2 only send and receive e-mails on the basis that Tele2 is not responsible for any such computer viruses, corruption or other interference or any consequences thereof. �It ought to be obvious that my views do not represent my employer's views.
>>>
>>> _______________________________________________
>>> linux-lvm mailing list
>>> linux-lvm@redhat.com
>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>
>>>
>>
>> _______________________________________________
>> linux-lvm mailing list
>> linux-lvm@redhat.com
>> https://www.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2009-12-30 13:00       ` brem belguebli
@ 2009-12-30 13:45         ` Simon Loewenthal/NL/Tele2
  2009-12-30 14:15           ` Simon Loewenthal/NL/Tele2
  0 siblings, 1 reply; 17+ messages in thread
From: Simon Loewenthal/NL/Tele2 @ 2009-12-30 13:45 UTC (permalink / raw)
  To: LVM general discussion and development

Yes, the dm names are the aliases I set-up in the multipathd.conf and
should not change.
I listed these below in my initial email.  In this example the alias is
called: dm-5_0111

# multipath -ll
dm-5_0111 (360060480000290300618533030313131) dm-5 EMC,SYMMETRIX
[size=17G][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:32 sdy        65:128 [active][ready]
 \_ 1:0:0:32 sdl        8:176  [active][ready]

Corresponding entry in multipathd.conf:
multipath  {
                wwid    360060480000290300618533030313131
                alias   dm-5_0111
                }

S.


brem belguebli wrote:
> What you have to be aware of is that /dev/dm names are volatile and
> can change across reboots as are /dev/sd names, never use them
> directly.
>
> If you are using device-mapper-multipath (not emcpowerpath) there is a
> "user_friendly_names" boolean setting in /etc/multipath.conf that
> would give you names such as /dev/mpath/mpath0 is set to yes.
>
> If set to no, it would give you names such as /dev/mpath/UUID.
>
> Both namings are persistent (stable across reboots) as multipath will
> base its binding on the disk UUID.
>
> see man multipath.conf to have full options listing.
>
> It allows you also to give custom names to devices by using the alias
> setting in multipath.conf.
>
> The filter you applied (your previous email) just prevents "r/..." LVM
> to check and so activate the device names that you rejected.
>
> Hope this'll help
>
> 2009/12/30 Simon Loewenthal/NL/Tele2 <simon.loewenthal@klunky.co.uk>:
>   
>> Thank-you Bren for the info., I am unsure how to specify the
>> preferred_devices using the muttipath:
>>  Should it be:
>>
>> preferred_names = [ "^/dev/dm-*/" , "^/dev/cciss/" ]
>>
>>
>> so that it uses these discs :
>> /dev/cciss/c0d0p4  (internal disc)
>> dm-6_010F       (multipathd alias for EMC disc)
>> dm-17_0012      (multipathd alias for EMC disc)
>> dm-13_0103      (multipathd alias for EMC disc)
>> dm-10_0109      (multipathd alias for EMC disc)
>>
>> The EMC discs are listed under /dev as :
>>  # ls -l /dev/dm-?
>> brw-r----- 1 root disk 253, 0 Oct 26 14:44 /dev/dm-0
>> brw-r----- 1 root disk 253, 1 Oct 26 14:44 /dev/dm-1
>> brw-r----- 1 root disk 253, 2 Oct 26 14:44 /dev/dm-2
>> brw-r----- 1 root disk 253, 3 Oct 30 10:16 /dev/dm-3
>> brw-r----- 1 root disk 253, 4 Dec  4 11:47 /dev/dm-4
>> brw-r----- 1 root disk 253, 5 Dec  4 11:47 /dev/dm-5
>> brw-r----- 1 root disk 253, 6 Dec  4 11:47 /dev/dm-6
>> brw-r----- 1 root disk 253, 7 Oct 26 14:44 /dev/dm-7
>> brw-r----- 1 root disk 253, 8 Dec  4 11:47 /dev/dm-8
>> brw-r----- 1 root disk 253, 9 Dec  4 11:47 /dev/dm-9
>>
>> ...but I do not see /dev/dm-6_010F.
>>
>>
>> S.
>>
>>
>>
>> brem belguebli wrote:
>>     
>>> Hi,
>>>
>>> see man 5 lvm.conf there is an option called preferred_names which is
>>> well explained
>>>
>>> It'll instruct lvm to use the preferred_names you configured in the
>>> lvm.conf file if they exist
>>>
>>> ie : preferred_names = "/dev/mpath/" will use /dev/mpath/XXX instead
>>> of /dev/mapper/XXX
>>>
>>>
>>> 2009/12/30 Simon Loewenthal/NL/Tele2 <simon.loewenthal@tele2.com>:
>>>
>>>       
>>>> I don't think this original Email made it through to the list, but I
>>>> think I have found an solution:
>>>>
>>>> In lvm.conf there is this line,
>>>> filter = [ "r|/dev/.*/by-path/.*|", "r|/dev/.*/by-id/.*|", "a/.*/" ]
>>>>
>>>> If I remove the portion "r|/dev/.*/by-id/.*|", so it is rewritten as,
>>>> filter = [ "r|/dev/.*/by-path/.*|", "a/.*/" ]
>>>> ...then it ought to ignore the device,
>>>> /dev/disk/by-id/scsi-360060480000290300618533030313133
>>>>
>>>> Is this correct?
>>>>
>>>> S.
>>>>
>>>> --
>>>> Simon Loewenthal/Tele2
>>>>
>>>>
>>>> Simon Loewenthal/NL/Tele2 wrote:
>>>>
>>>>         
>>>>> Dear all,
>>>>>
>>>>>     I have a volume group that is currently using discs directly
>>>>> presented from EMC e.g
>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313042 .
>>>>>
>>>>> An lvdisplay -v shows these PVs:
>>>>> # vgdisplay -v vg_mds
>>>>>     Using volume group(s) on command line
>>>>>     Finding volume group "vg_mds"
>>>>>   --- Volume group ---
>>>>>   VG Name               vg_mds
>>>>>   System ID
>>>>>   Format                lvm2
>>>>>   Metadata Areas        12
>>>>>   Metadata Sequence No  4
>>>>>   VG Access             read/write
>>>>>   VG Status             resizable
>>>>>   MAX LV                0
>>>>>   Cur LV                1
>>>>>   Open LV               1
>>>>>   Max PV                0
>>>>>   Cur PV                12
>>>>>   Act PV                12
>>>>>   VG Size               202.12 GB
>>>>>   PE Size               32.00 MB
>>>>>   Total PE              6468
>>>>>   Alloc PE / Size       6468 / 202.12 GB
>>>>>   Free  PE / Size       0 / 0
>>>>>   VG UUID               Wnk1a8-xdVf-RorP-ZxPE-Z3D9-5fp1-2o4hHs
>>>>>
>>>>>   --- Logical volume ---
>>>>>   LV Name                /dev/vg_mds/lvol_mds
>>>>>   VG Name                vg_mds
>>>>>   LV UUID                TErCZW-senu-YR3k-I25n-Tqk9-BK2k-3mQY3S
>>>>>   LV Write Access        read/write
>>>>>   LV Status              available
>>>>>   # open                 1
>>>>>   LV Size                202.12 GB
>>>>>   Current LE             6468
>>>>>   Segments               12
>>>>>   Allocation             inherit
>>>>>   Read ahead sectors     0
>>>>>   Block device           253:7
>>>>>
>>>>>   --- Physical volumes ---
>>>>>   PV Name
>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313133
>>>>>   PV UUID               255V1X-uMZp-Lod1-3jsa-cCGd-JaNZ-v0dEXn
>>>>>   PV Status             allocatable
>>>>>   Total PE / Free PE    539 / 0
>>>>>
>>>>>   PV Name
>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313131
>>>>>   PV UUID               RU5WZK-G3hY-lXCD-F6Kj-PcJA-DcbE-iV17P7
>>>>>   PV Status             allocatable
>>>>>   Total PE / Free PE    539 / 0
>>>>>
>>>>>   PV Name
>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313046
>>>>>   PV UUID               c3DVym-lzdw-MgS6-acQI-BcUD-UOGq-iG6hSe
>>>>>   PV Status             allocatable
>>>>>   Total PE / Free PE    539 / 0
>>>>>
>>>>>   PV Name
>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313044
>>>>>   PV UUID               d7VD54-KmXZ-t8eX-dvph-9lSp-ym03-Lc62sI
>>>>>   PV Status             allocatable
>>>>>   Total PE / Free PE    539 / 0
>>>>>
>>>>>   PV Name
>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313042
>>>>>   PV UUID               n32oAY-soe3-odYI-SAFQ-yM7v-FRaw-e9hS63
>>>>>   PV Status             allocatable
>>>>>   Total PE / Free PE    539 / 0
>>>>>
>>>>>   PV Name
>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313039
>>>>>   PV UUID               hT2hZ7-XAZr-ZUte-rzLV-kwFX-Jtih-K3OgZe
>>>>>   PV Status             allocatable
>>>>>   Total PE / Free PE    539 / 0
>>>>>
>>>>>   PV Name
>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313037
>>>>>   PV UUID               ut4fEx-R0c2-lA4y-qS3F-SYfp-Chuz-2SrvTo
>>>>>   PV Status             allocatable
>>>>>   Total PE / Free PE    539 / 0
>>>>>
>>>>>   PV Name
>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313035
>>>>>   PV UUID               BMJ8LA-b0L7-aAoK-4WqG-MLdU-s8Y8-xGib2s
>>>>>   PV Status             allocatable
>>>>>   Total PE / Free PE    539 / 0
>>>>>
>>>>>   PV Name
>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313033
>>>>>   PV UUID               uSasZ1-96rT-ngGN-Wfcr-fBNg-ceM0-GaccVU
>>>>>   PV Status             allocatable
>>>>>   Total PE / Free PE    539 / 0
>>>>>
>>>>>   PV Name
>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313031
>>>>>   PV UUID               R15yAf-t1YO-Z0Dx-4n2G-oTyD-Secp-2igMJc
>>>>>   PV Status             allocatable
>>>>>   Total PE / Free PE    539 / 0
>>>>>
>>>>>   PV Name
>>>>> /dev/disk/by-id/scsi-360060480000290300618533030304646
>>>>>   PV UUID               nrhhx1-7AxM-VmVv-sRY5-TLR7-UAEE-wBUIMB
>>>>>   PV Status             allocatable
>>>>>   Total PE / Free PE    539 / 0
>>>>>
>>>>>   PV Name
>>>>> /dev/disk/by-id/scsi-360060480000290300618533030304644
>>>>>   PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
>>>>>   PV Status             allocatable
>>>>>   Total PE / Free PE    539 / 0
>>>>>
>>>>>
>>>>> I want to export this volume group and inport it again using
>>>>> multipathing.  I have configured the multipathing thus,
>>>>>  # multipath -ll
>>>>> dm-6_010F (360060480000290300618533030313046) dm-6 EMC,SYMMETRIX
>>>>> [size=17G][features=0][hwhandler=0]
>>>>> \_ round-robin 0 [prio=2][active]
>>>>>  \_ 0:0:0:31 sdx        65:112 [active][ready]
>>>>>  \_ 1:0:0:31 sdk        8:160  [active][ready]
>>>>> dm-17_0012 (360060480000290300618533030303132) dm-17 EMC,SYMMETRIX
>>>>> [size=4.7M][features=0][hwhandler=0]
>>>>> \_ round-robin 0 [prio=2][active]
>>>>>  \_ 0:0:0:0  sdn        8:208  [active][ready]
>>>>>  \_ 1:0:0:0  sda        8:0    [active][ready]
>>>>> dm-13_0103 (360060480000290300618533030313033) dm-13 EMC,SYMMETRIX
>>>>> [size=17G][features=0][hwhandler=0]
>>>>> \_ round-robin 0 [prio=2][active]
>>>>>  \_ 0:0:0:25 sdr        65:16  [active][ready]
>>>>>  \_ 1:0:0:25 sde        8:64   [active][ready]
>>>>> dm-10_0109 (360060480000290300618533030313039) dm-10 EMC,SYMMETRIX
>>>>> [size=17G][features=0][hwhandler=0]
>>>>> \_ round-robin 0 [prio=2][active]
>>>>>  \_ 0:0:0:28 sdu        65:64  [active][ready]
>>>>>  \_ 1:0:0:28 sdh        8:112  [active][ready]
>>>>> dm-14_0101 (360060480000290300618533030313031) dm-14 EMC,SYMMETRIX
>>>>> [size=17G][features=0][hwhandler=0]
>>>>> \_ round-robin 0 [prio=2][active]
>>>>>  \_ 0:0:0:24 sdq        65:0   [active][ready]
>>>>>  \_ 1:0:0:24 sdd        8:48   [active][ready]
>>>>> dm-8_010D (360060480000290300618533030313044) dm-8 EMC,SYMMETRIX
>>>>> [size=17G][features=0][hwhandler=0]
>>>>> \_ round-robin 0 [prio=2][active]
>>>>>  \_ 0:0:0:30 sdw        65:96  [active][ready]
>>>>>  \_ 1:0:0:30 sdj        8:144  [active][ready]
>>>>> dm-15_00FF (360060480000290300618533030304646) dm-15 EMC,SYMMETRIX
>>>>> [size=17G][features=0][hwhandler=0]
>>>>> \_ round-robin 0 [prio=2][active]
>>>>>  \_ 0:0:0:23 sdp        8:240  [active][ready]
>>>>>  \_ 1:0:0:23 sdc        8:32   [active][ready]
>>>>> dm-11_0107 (360060480000290300618533030313037) dm-11 EMC,SYMMETRIX
>>>>> [size=17G][features=0][hwhandler=0]
>>>>> \_ round-robin 0 [prio=2][active]
>>>>>  \_ 0:0:0:27 sdt        65:48  [active][ready]
>>>>>  \_ 1:0:0:27 sdg        8:96   [active][ready]
>>>>> dm-4_0113 (360060480000290300618533030313133) dm-4 EMC,SYMMETRIX
>>>>> [size=17G][features=0][hwhandler=0]
>>>>> \_ round-robin 0 [prio=2][active]
>>>>>  \_ 0:0:0:33 sdz        65:144 [active][ready]
>>>>>  \_ 1:0:0:33 sdm        8:192  [active][ready]
>>>>> dm-9_010B (360060480000290300618533030313042) dm-9 EMC,SYMMETRIX
>>>>> [size=17G][features=0][hwhandler=0]
>>>>> \_ round-robin 0 [prio=2][active]
>>>>>  \_ 0:0:0:29 sdv        65:80  [active][ready]
>>>>>  \_ 1:0:0:29 sdi        8:128  [active][ready]
>>>>> dm-16_00FD (360060480000290300618533030304644) dm-16 EMC,SYMMETRIX
>>>>> [size=17G][features=0][hwhandler=0]
>>>>> \_ round-robin 0 [prio=2][active]
>>>>>  \_ 0:0:0:22 sdo        8:224  [active][ready]
>>>>>  \_ 1:0:0:22 sdb        8:16   [active][ready]
>>>>> dm-12_0105 (360060480000290300618533030313035) dm-12 EMC,SYMMETRIX
>>>>> [size=17G][features=0][hwhandler=0]
>>>>> \_ round-robin 0 [prio=2][active]
>>>>>  \_ 0:0:0:26 sds        65:32  [active][ready]
>>>>>  \_ 1:0:0:26 sdf        8:80   [active][ready]
>>>>> dm-5_0111 (360060480000290300618533030313131) dm-5 EMC,SYMMETRIX
>>>>> [size=17G][features=0][hwhandler=0]
>>>>> \_ round-robin 0 [prio=2][active]
>>>>>  \_ 0:0:0:32 sdy        65:128 [active][ready]
>>>>>  \_ 1:0:0:32 sdl        8:176  [active][ready]
>>>>>
>>>>> Device mapper reports this:
>>>>> # dmsetup ls
>>>>> dm-6_010F    (253, 6)
>>>>> dm-17_0012    (253, 17)
>>>>> dm-13_0103    (253, 13)
>>>>> dm-10_0109    (253, 10)
>>>>> vg00-app052    (253, 3)
>>>>> vg00-xen    (253, 2)
>>>>> vg00-usr    (253, 0)
>>>>> vg00-var    (253, 1)
>>>>> dm-14_0101    (253, 14)
>>>>> dm-8_010D    (253, 8)
>>>>> dm-15_00FF    (253, 15)
>>>>> dm-11_0107    (253, 11)
>>>>> dm-4_0113    (253, 4)
>>>>> vg_mds-lvol_mds    (253, 7)
>>>>> dm-9_010B    (253, 9)
>>>>> dm-16_00FD    (253, 16)
>>>>> dm-12_0105    (253, 12)
>>>>> dm-5_0111    (253, 5)
>>>>>
>>>>>
>>>>> What I do not understand is that surly when I perform a vgscan how will
>>>>> it decide to query only the devices presented from the multipathd, and
>>>>> ignore those presented via the dev/disk/by-id/scsi-nnnnnnnnnn?  Won't it
>>>>> see two vg_mds volumes instead of only those volumes that lie on the
>>>>> multipathed discs, which are the same pshycial discs as the disk/by-id?
>>>>>
>>>>> My plan of action is currently:
>>>>>     vgchange -a n vg_mds
>>>>>     vgexport -m /tmp/vg_mds.map mds
>>>>>     vgexport -f /tmp/vg_mds.pv mds
>>>>>     vgscan
>>>>>     vgchange -y a vg_mds
>>>>>     vgimport vg_mds /*OR instead do it the long way on the next line*  /
>>>>>         vgscan
>>>>>         mkdir /dev/vg_mds
>>>>>         mknod /dev/vg_mds/group c 64 0xNN0000
>>>>>         vgimport -v -s -m /tmp/vg_mds.map /dev/vg_mds
>>>>>
>>>>> I do not see how to tell it to ignore the non-multipathed disc, or has
>>>>> multipathd or LVM have some preference for mutlipath discs over
>>>>> non-multipathed discs, and if so then what is the logic behind the decision?
>>>>>
>>>>> Any help to further my understanding would be gratefully appreciated.
>>>>>
>>>>> Best wishes, S.
>>>>>
>>>>> PS. I am using SLES, but this was the only mailinglist I found for LVM
>>>>> so I subscribed to it.  I think that LVM and multipathd implementations
>>>>> are reasonably similar across Linux distos. Ergo concepts here are
>>>>> applicable to Suse.  The kernel I am using is a xen enabled host (not a
>>>>> guest): 2.6.16.60-0.27-xen #1 SMP.
>>>>>
>>>>>
>>>>>
>>>>>           
>>>> --
>>>> Simon Loewenthal/Tele2
>>>>
>>>> ******** IMPORTANT NOTICE ********
>>>> Please repect the X-Reply to klunky.co.uk. PGP available 0xD86A5A17.
>>>> S/MIME PKCS12 key available for Lotus Notes: Please ask me for it.
>>>> This e-mail (including any attachments) may contain information that is confidential or otherwise protected from disclosure and it is intended only for the addressees. If you are not the intended recipient, please note that any copying, distribution or other use of information contained in this e-mail (and its attachments) is not allowed. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message (including any attachments) from your system.
>>>> Please note that e-mail messages may contain computer viruses or other defects, may not be accurately replicated on other systems, or may be subject of unauthorized interception or other interference without the knowledge of sender or recipient. Tele2 only send and receive e-mails on the basis that Tele2 is not responsible for any such computer viruses, corruption or other interference or any consequences thereof.  It ought to be obvious that my views do not represent my employer's views.
>>>>
>>>> _______________________________________________
>>>> linux-lvm mailing list
>>>> linux-lvm@redhat.com
>>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>>
>>>>
>>>>         
>>> _______________________________________________
>>> linux-lvm mailing list
>>> linux-lvm@redhat.com
>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>
>>>       
>> _______________________________________________
>> linux-lvm mailing list
>> linux-lvm@redhat.com
>> https://www.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>
>>     
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>   

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2009-12-30 13:45         ` Simon Loewenthal/NL/Tele2
@ 2009-12-30 14:15           ` Simon Loewenthal/NL/Tele2
  0 siblings, 0 replies; 17+ messages in thread
From: Simon Loewenthal/NL/Tele2 @ 2009-12-30 14:15 UTC (permalink / raw)
  To: LVM general discussion and development

I have changed the alias from the dm name to  EMC_{LUNid}  e.g  EMC_0103
This should make more sence.

EMC_0103 (360060480000290300618533030313033) dm-13 EMC,SYMMETRIX
[size=17G][features=0][hwhandler=0]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:25 sdr        65:16  [active][ready]
 \_ 1:0:0:25 sde        8:64   [active][ready]

# ls /dev/mapper
EMC_0012  EMC_00FF  EMC_0103  EMC_0107  EMC_010B  EMC_010F  EMC_0113 
vg00-app052  vg00-var  vg_mds-lvol_mds
EMC_00FD  EMC_0101  EMC_0105  EMC_0109  EMC_010D  EMC_0111  control  
vg00-usr     vg00-xen


Ought the preferred_devices to be:

preferred_names = [ "^/dev/mapper/" , "^/dev/cciss/" ]

S.


Simon Loewenthal/NL/Tele2 wrote:
> Yes, the dm names are the aliases I set-up in the multipathd.conf and
> should not change.
> I listed these below in my initial email.  In this example the alias is
> called: dm-5_0111
>
> # multipath -ll
> dm-5_0111 (360060480000290300618533030313131) dm-5 EMC,SYMMETRIX
> [size=17G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:0:32 sdy        65:128 [active][ready]
>  \_ 1:0:0:32 sdl        8:176  [active][ready]
>
> Corresponding entry in multipathd.conf:
> multipath  {
>                 wwid    360060480000290300618533030313131
>                 alias   dm-5_0111
>                 }
>
> S.
>
>
> brem belguebli wrote:
>   
>> What you have to be aware of is that /dev/dm names are volatile and
>> can change across reboots as are /dev/sd names, never use them
>> directly.
>>
>> If you are using device-mapper-multipath (not emcpowerpath) there is a
>> "user_friendly_names" boolean setting in /etc/multipath.conf that
>> would give you names such as /dev/mpath/mpath0 is set to yes.
>>
>> If set to no, it would give you names such as /dev/mpath/UUID.
>>
>> Both namings are persistent (stable across reboots) as multipath will
>> base its binding on the disk UUID.
>>
>> see man multipath.conf to have full options listing.
>>
>> It allows you also to give custom names to devices by using the alias
>> setting in multipath.conf.
>>
>> The filter you applied (your previous email) just prevents "r/..." LVM
>> to check and so activate the device names that you rejected.
>>
>> Hope this'll help
>>
>> 2009/12/30 Simon Loewenthal/NL/Tele2 <simon.loewenthal@klunky.co.uk>:
>>   
>>     
>>> Thank-you Bren for the info., I am unsure how to specify the
>>> preferred_devices using the muttipath:
>>>  Should it be:
>>>
>>> preferred_names = [ "^/dev/dm-*/" , "^/dev/cciss/" ]
>>>
>>>
>>> so that it uses these discs :
>>> /dev/cciss/c0d0p4  (internal disc)
>>> dm-6_010F       (multipathd alias for EMC disc)
>>> dm-17_0012      (multipathd alias for EMC disc)
>>> dm-13_0103      (multipathd alias for EMC disc)
>>> dm-10_0109      (multipathd alias for EMC disc)
>>>
>>> The EMC discs are listed under /dev as :
>>>  # ls -l /dev/dm-?
>>> brw-r----- 1 root disk 253, 0 Oct 26 14:44 /dev/dm-0
>>> brw-r----- 1 root disk 253, 1 Oct 26 14:44 /dev/dm-1
>>> brw-r----- 1 root disk 253, 2 Oct 26 14:44 /dev/dm-2
>>> brw-r----- 1 root disk 253, 3 Oct 30 10:16 /dev/dm-3
>>> brw-r----- 1 root disk 253, 4 Dec  4 11:47 /dev/dm-4
>>> brw-r----- 1 root disk 253, 5 Dec  4 11:47 /dev/dm-5
>>> brw-r----- 1 root disk 253, 6 Dec  4 11:47 /dev/dm-6
>>> brw-r----- 1 root disk 253, 7 Oct 26 14:44 /dev/dm-7
>>> brw-r----- 1 root disk 253, 8 Dec  4 11:47 /dev/dm-8
>>> brw-r----- 1 root disk 253, 9 Dec  4 11:47 /dev/dm-9
>>>
>>> ...but I do not see /dev/dm-6_010F.
>>>
>>>
>>> S.
>>>
>>>
>>>
>>> brem belguebli wrote:
>>>     
>>>       
>>>> Hi,
>>>>
>>>> see man 5 lvm.conf there is an option called preferred_names which is
>>>> well explained
>>>>
>>>> It'll instruct lvm to use the preferred_names you configured in the
>>>> lvm.conf file if they exist
>>>>
>>>> ie : preferred_names = "/dev/mpath/" will use /dev/mpath/XXX instead
>>>> of /dev/mapper/XXX
>>>>
>>>>
>>>> 2009/12/30 Simon Loewenthal/NL/Tele2 <simon.loewenthal@tele2.com>:
>>>>
>>>>       
>>>>         
>>>>> I don't think this original Email made it through to the list, but I
>>>>> think I have found an solution:
>>>>>
>>>>> In lvm.conf there is this line,
>>>>> filter = [ "r|/dev/.*/by-path/.*|", "r|/dev/.*/by-id/.*|", "a/.*/" ]
>>>>>
>>>>> If I remove the portion "r|/dev/.*/by-id/.*|", so it is rewritten as,
>>>>> filter = [ "r|/dev/.*/by-path/.*|", "a/.*/" ]
>>>>> ...then it ought to ignore the device,
>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313133
>>>>>
>>>>> Is this correct?
>>>>>
>>>>> S.
>>>>>
>>>>> --
>>>>> Simon Loewenthal/Tele2
>>>>>
>>>>>
>>>>> Simon Loewenthal/NL/Tele2 wrote:
>>>>>
>>>>>         
>>>>>           
>>>>>> Dear all,
>>>>>>
>>>>>>     I have a volume group that is currently using discs directly
>>>>>> presented from EMC e.g
>>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313042 .
>>>>>>
>>>>>> An lvdisplay -v shows these PVs:
>>>>>> # vgdisplay -v vg_mds
>>>>>>     Using volume group(s) on command line
>>>>>>     Finding volume group "vg_mds"
>>>>>>   --- Volume group ---
>>>>>>   VG Name               vg_mds
>>>>>>   System ID
>>>>>>   Format                lvm2
>>>>>>   Metadata Areas        12
>>>>>>   Metadata Sequence No  4
>>>>>>   VG Access             read/write
>>>>>>   VG Status             resizable
>>>>>>   MAX LV                0
>>>>>>   Cur LV                1
>>>>>>   Open LV               1
>>>>>>   Max PV                0
>>>>>>   Cur PV                12
>>>>>>   Act PV                12
>>>>>>   VG Size               202.12 GB
>>>>>>   PE Size               32.00 MB
>>>>>>   Total PE              6468
>>>>>>   Alloc PE / Size       6468 / 202.12 GB
>>>>>>   Free  PE / Size       0 / 0
>>>>>>   VG UUID               Wnk1a8-xdVf-RorP-ZxPE-Z3D9-5fp1-2o4hHs
>>>>>>
>>>>>>   --- Logical volume ---
>>>>>>   LV Name                /dev/vg_mds/lvol_mds
>>>>>>   VG Name                vg_mds
>>>>>>   LV UUID                TErCZW-senu-YR3k-I25n-Tqk9-BK2k-3mQY3S
>>>>>>   LV Write Access        read/write
>>>>>>   LV Status              available
>>>>>>   # open                 1
>>>>>>   LV Size                202.12 GB
>>>>>>   Current LE             6468
>>>>>>   Segments               12
>>>>>>   Allocation             inherit
>>>>>>   Read ahead sectors     0
>>>>>>   Block device           253:7
>>>>>>
>>>>>>   --- Physical volumes ---
>>>>>>   PV Name
>>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313133
>>>>>>   PV UUID               255V1X-uMZp-Lod1-3jsa-cCGd-JaNZ-v0dEXn
>>>>>>   PV Status             allocatable
>>>>>>   Total PE / Free PE    539 / 0
>>>>>>
>>>>>>   PV Name
>>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313131
>>>>>>   PV UUID               RU5WZK-G3hY-lXCD-F6Kj-PcJA-DcbE-iV17P7
>>>>>>   PV Status             allocatable
>>>>>>   Total PE / Free PE    539 / 0
>>>>>>
>>>>>>   PV Name
>>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313046
>>>>>>   PV UUID               c3DVym-lzdw-MgS6-acQI-BcUD-UOGq-iG6hSe
>>>>>>   PV Status             allocatable
>>>>>>   Total PE / Free PE    539 / 0
>>>>>>
>>>>>>   PV Name
>>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313044
>>>>>>   PV UUID               d7VD54-KmXZ-t8eX-dvph-9lSp-ym03-Lc62sI
>>>>>>   PV Status             allocatable
>>>>>>   Total PE / Free PE    539 / 0
>>>>>>
>>>>>>   PV Name
>>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313042
>>>>>>   PV UUID               n32oAY-soe3-odYI-SAFQ-yM7v-FRaw-e9hS63
>>>>>>   PV Status             allocatable
>>>>>>   Total PE / Free PE    539 / 0
>>>>>>
>>>>>>   PV Name
>>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313039
>>>>>>   PV UUID               hT2hZ7-XAZr-ZUte-rzLV-kwFX-Jtih-K3OgZe
>>>>>>   PV Status             allocatable
>>>>>>   Total PE / Free PE    539 / 0
>>>>>>
>>>>>>   PV Name
>>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313037
>>>>>>   PV UUID               ut4fEx-R0c2-lA4y-qS3F-SYfp-Chuz-2SrvTo
>>>>>>   PV Status             allocatable
>>>>>>   Total PE / Free PE    539 / 0
>>>>>>
>>>>>>   PV Name
>>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313035
>>>>>>   PV UUID               BMJ8LA-b0L7-aAoK-4WqG-MLdU-s8Y8-xGib2s
>>>>>>   PV Status             allocatable
>>>>>>   Total PE / Free PE    539 / 0
>>>>>>
>>>>>>   PV Name
>>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313033
>>>>>>   PV UUID               uSasZ1-96rT-ngGN-Wfcr-fBNg-ceM0-GaccVU
>>>>>>   PV Status             allocatable
>>>>>>   Total PE / Free PE    539 / 0
>>>>>>
>>>>>>   PV Name
>>>>>> /dev/disk/by-id/scsi-360060480000290300618533030313031
>>>>>>   PV UUID               R15yAf-t1YO-Z0Dx-4n2G-oTyD-Secp-2igMJc
>>>>>>   PV Status             allocatable
>>>>>>   Total PE / Free PE    539 / 0
>>>>>>
>>>>>>   PV Name
>>>>>> /dev/disk/by-id/scsi-360060480000290300618533030304646
>>>>>>   PV UUID               nrhhx1-7AxM-VmVv-sRY5-TLR7-UAEE-wBUIMB
>>>>>>   PV Status             allocatable
>>>>>>   Total PE / Free PE    539 / 0
>>>>>>
>>>>>>   PV Name
>>>>>> /dev/disk/by-id/scsi-360060480000290300618533030304644
>>>>>>   PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
>>>>>>   PV Status             allocatable
>>>>>>   Total PE / Free PE    539 / 0
>>>>>>
>>>>>>
>>>>>> I want to export this volume group and inport it again using
>>>>>> multipathing.  I have configured the multipathing thus,
>>>>>>  # multipath -ll
>>>>>> dm-6_010F (360060480000290300618533030313046) dm-6 EMC,SYMMETRIX
>>>>>> [size=17G][features=0][hwhandler=0]
>>>>>> \_ round-robin 0 [prio=2][active]
>>>>>>  \_ 0:0:0:31 sdx        65:112 [active][ready]
>>>>>>  \_ 1:0:0:31 sdk        8:160  [active][ready]
>>>>>> dm-17_0012 (360060480000290300618533030303132) dm-17 EMC,SYMMETRIX
>>>>>> [size=4.7M][features=0][hwhandler=0]
>>>>>> \_ round-robin 0 [prio=2][active]
>>>>>>  \_ 0:0:0:0  sdn        8:208  [active][ready]
>>>>>>  \_ 1:0:0:0  sda        8:0    [active][ready]
>>>>>> dm-13_0103 (360060480000290300618533030313033) dm-13 EMC,SYMMETRIX
>>>>>> [size=17G][features=0][hwhandler=0]
>>>>>> \_ round-robin 0 [prio=2][active]
>>>>>>  \_ 0:0:0:25 sdr        65:16  [active][ready]
>>>>>>  \_ 1:0:0:25 sde        8:64   [active][ready]
>>>>>> dm-10_0109 (360060480000290300618533030313039) dm-10 EMC,SYMMETRIX
>>>>>> [size=17G][features=0][hwhandler=0]
>>>>>> \_ round-robin 0 [prio=2][active]
>>>>>>  \_ 0:0:0:28 sdu        65:64  [active][ready]
>>>>>>  \_ 1:0:0:28 sdh        8:112  [active][ready]
>>>>>> dm-14_0101 (360060480000290300618533030313031) dm-14 EMC,SYMMETRIX
>>>>>> [size=17G][features=0][hwhandler=0]
>>>>>> \_ round-robin 0 [prio=2][active]
>>>>>>  \_ 0:0:0:24 sdq        65:0   [active][ready]
>>>>>>  \_ 1:0:0:24 sdd        8:48   [active][ready]
>>>>>> dm-8_010D (360060480000290300618533030313044) dm-8 EMC,SYMMETRIX
>>>>>> [size=17G][features=0][hwhandler=0]
>>>>>> \_ round-robin 0 [prio=2][active]
>>>>>>  \_ 0:0:0:30 sdw        65:96  [active][ready]
>>>>>>  \_ 1:0:0:30 sdj        8:144  [active][ready]
>>>>>> dm-15_00FF (360060480000290300618533030304646) dm-15 EMC,SYMMETRIX
>>>>>> [size=17G][features=0][hwhandler=0]
>>>>>> \_ round-robin 0 [prio=2][active]
>>>>>>  \_ 0:0:0:23 sdp        8:240  [active][ready]
>>>>>>  \_ 1:0:0:23 sdc        8:32   [active][ready]
>>>>>> dm-11_0107 (360060480000290300618533030313037) dm-11 EMC,SYMMETRIX
>>>>>> [size=17G][features=0][hwhandler=0]
>>>>>> \_ round-robin 0 [prio=2][active]
>>>>>>  \_ 0:0:0:27 sdt        65:48  [active][ready]
>>>>>>  \_ 1:0:0:27 sdg        8:96   [active][ready]
>>>>>> dm-4_0113 (360060480000290300618533030313133) dm-4 EMC,SYMMETRIX
>>>>>> [size=17G][features=0][hwhandler=0]
>>>>>> \_ round-robin 0 [prio=2][active]
>>>>>>  \_ 0:0:0:33 sdz        65:144 [active][ready]
>>>>>>  \_ 1:0:0:33 sdm        8:192  [active][ready]
>>>>>> dm-9_010B (360060480000290300618533030313042) dm-9 EMC,SYMMETRIX
>>>>>> [size=17G][features=0][hwhandler=0]
>>>>>> \_ round-robin 0 [prio=2][active]
>>>>>>  \_ 0:0:0:29 sdv        65:80  [active][ready]
>>>>>>  \_ 1:0:0:29 sdi        8:128  [active][ready]
>>>>>> dm-16_00FD (360060480000290300618533030304644) dm-16 EMC,SYMMETRIX
>>>>>> [size=17G][features=0][hwhandler=0]
>>>>>> \_ round-robin 0 [prio=2][active]
>>>>>>  \_ 0:0:0:22 sdo        8:224  [active][ready]
>>>>>>  \_ 1:0:0:22 sdb        8:16   [active][ready]
>>>>>> dm-12_0105 (360060480000290300618533030313035) dm-12 EMC,SYMMETRIX
>>>>>> [size=17G][features=0][hwhandler=0]
>>>>>> \_ round-robin 0 [prio=2][active]
>>>>>>  \_ 0:0:0:26 sds        65:32  [active][ready]
>>>>>>  \_ 1:0:0:26 sdf        8:80   [active][ready]
>>>>>> dm-5_0111 (360060480000290300618533030313131) dm-5 EMC,SYMMETRIX
>>>>>> [size=17G][features=0][hwhandler=0]
>>>>>> \_ round-robin 0 [prio=2][active]
>>>>>>  \_ 0:0:0:32 sdy        65:128 [active][ready]
>>>>>>  \_ 1:0:0:32 sdl        8:176  [active][ready]
>>>>>>
>>>>>> Device mapper reports this:
>>>>>> # dmsetup ls
>>>>>> dm-6_010F    (253, 6)
>>>>>> dm-17_0012    (253, 17)
>>>>>> dm-13_0103    (253, 13)
>>>>>> dm-10_0109    (253, 10)
>>>>>> vg00-app052    (253, 3)
>>>>>> vg00-xen    (253, 2)
>>>>>> vg00-usr    (253, 0)
>>>>>> vg00-var    (253, 1)
>>>>>> dm-14_0101    (253, 14)
>>>>>> dm-8_010D    (253, 8)
>>>>>> dm-15_00FF    (253, 15)
>>>>>> dm-11_0107    (253, 11)
>>>>>> dm-4_0113    (253, 4)
>>>>>> vg_mds-lvol_mds    (253, 7)
>>>>>> dm-9_010B    (253, 9)
>>>>>> dm-16_00FD    (253, 16)
>>>>>> dm-12_0105    (253, 12)
>>>>>> dm-5_0111    (253, 5)
>>>>>>
>>>>>>
>>>>>> What I do not understand is that surly when I perform a vgscan how will
>>>>>> it decide to query only the devices presented from the multipathd, and
>>>>>> ignore those presented via the dev/disk/by-id/scsi-nnnnnnnnnn?  Won't it
>>>>>> see two vg_mds volumes instead of only those volumes that lie on the
>>>>>> multipathed discs, which are the same pshycial discs as the disk/by-id?
>>>>>>
>>>>>> My plan of action is currently:
>>>>>>     vgchange -a n vg_mds
>>>>>>     vgexport -m /tmp/vg_mds.map mds
>>>>>>     vgexport -f /tmp/vg_mds.pv mds
>>>>>>     vgscan
>>>>>>     vgchange -y a vg_mds
>>>>>>     vgimport vg_mds /*OR instead do it the long way on the next line*  /
>>>>>>         vgscan
>>>>>>         mkdir /dev/vg_mds
>>>>>>         mknod /dev/vg_mds/group c 64 0xNN0000
>>>>>>         vgimport -v -s -m /tmp/vg_mds.map /dev/vg_mds
>>>>>>
>>>>>> I do not see how to tell it to ignore the non-multipathed disc, or has
>>>>>> multipathd or LVM have some preference for mutlipath discs over
>>>>>> non-multipathed discs, and if so then what is the logic behind the decision?
>>>>>>
>>>>>> Any help to further my understanding would be gratefully appreciated.
>>>>>>
>>>>>> Best wishes, S.
>>>>>>
>>>>>> PS. I am using SLES, but this was the only mailinglist I found for LVM
>>>>>> so I subscribed to it.  I think that LVM and multipathd implementations
>>>>>> are reasonably similar across Linux distos. Ergo concepts here are
>>>>>> applicable to Suse.  The kernel I am using is a xen enabled host (not a
>>>>>> guest): 2.6.16.60-0.27-xen #1 SMP.
>>>>>>
>>>>>>
>>>>>>
>>>>>>           
>>>>>>             
>>>>> --
>>>>> Simon Loewenthal/Tele2
>>>>>
>>>>> ******** IMPORTANT NOTICE ********
>>>>> Please repect the X-Reply to klunky.co.uk. PGP available 0xD86A5A17.
>>>>> S/MIME PKCS12 key available for Lotus Notes: Please ask me for it.
>>>>> This e-mail (including any attachments) may contain information that is confidential or otherwise protected from disclosure and it is intended only for the addressees. If you are not the intended recipient, please note that any copying, distribution or other use of information contained in this e-mail (and its attachments) is not allowed. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message (including any attachments) from your system.
>>>>> Please note that e-mail messages may contain computer viruses or other defects, may not be accurately replicated on other systems, or may be subject of unauthorized interception or other interference without the knowledge of sender or recipient. Tele2 only send and receive e-mails on the basis that Tele2 is not responsible for any such computer viruses, corruption or other interference or any consequences thereof.  It ought to be obvious that my views do not represent my employer's views.
>>>>>
>>>>> _______________________________________________
>>>>> linux-lvm mailing list
>>>>> linux-lvm@redhat.com
>>>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>>>
>>>>>
>>>>>         
>>>>>           
>>>> _______________________________________________
>>>> linux-lvm mailing list
>>>> linux-lvm@redhat.com
>>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>>
>>>>       
>>>>         
>>> _______________________________________________
>>> linux-lvm mailing list
>>> linux-lvm@redhat.com
>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>
>>>     
>>>       
>> _______________________________________________
>> linux-lvm mailing list
>> linux-lvm@redhat.com
>> https://www.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>   
>>     
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>   

-- 
Simon Loewenthal/Tele2
GSM: +31 6 2000 5427

******** IMPORTANT NOTICE ********
Please repect the X-Reply to klunky.co.uk. PGP available 0xD86A5A17. 
S/MIME PKCS12 key available for Lotus Notes: Please ask me for it.
This e-mail (including any attachments) may contain information that is confidential or otherwise protected from disclosure and it is intended only for the addressees. If you are not the intended recipient, please note that any copying, distribution or other use of information contained in this e-mail (and its attachments) is not allowed. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message (including any attachments) from your system.
Please note that e-mail messages may contain computer viruses or other defects, may not be accurately replicated on other systems, or may be subject of unauthorized interception or other interference without the knowledge of sender or recipient. Tele2 only send and receive e-mails on the basis that Tele2 is not responsible for any such computer viruses, corruption or other interference or any consequences thereof.  It ought to be obvious that my views do not represent my employer's views.

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2009-12-30 11:52   ` brem belguebli
  2009-12-30 12:37     ` Simon Loewenthal/NL/Tele2
@ 2010-01-04 12:54     ` Bryn M. Reeves
  2010-01-04 13:17       ` brem belguebli
  1 sibling, 1 reply; 17+ messages in thread
From: Bryn M. Reeves @ 2010-01-04 12:54 UTC (permalink / raw)
  To: LVM general discussion and development

On Wed, 2009-12-30 at 12:52 +0100, brem belguebli wrote:
> Hi,
> 
> see man 5 lvm.conf there is an option called preferred_names which is
> well explained
> 
> It'll instruct lvm to use the preferred_names you configured in the
> lvm.conf file if they exist
> 
> ie : preferred_names = "/dev/mpath/" will use /dev/mpath/XXX instead
> of /dev/mapper/XXX

It's best not to use the symlinks in /dev/mpath - they are not always
reliable. Use the device nodes created in /dev/mapper instead.

Regards,
Bryn.

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2010-01-04 12:54     ` Bryn M. Reeves
@ 2010-01-04 13:17       ` brem belguebli
  2010-01-05 10:52         ` Simon Loewenthal/NL/Tele2
  0 siblings, 1 reply; 17+ messages in thread
From: brem belguebli @ 2010-01-04 13:17 UTC (permalink / raw)
  To: LVM general discussion and development

Hi,

Never had no problem with it.

The only problem I've hit was due to the binding file being, by
default, located in /var/lib/multipath, which is in my setup on a
separate LV than /, during boot time the devices were not correctly
created.

Just had to switch the binding file to /etc and now no more problem.

extract of my /etc/multipath.conf :


defaults {
...
        flush_on_last_del       yes
        user_friendly_names     yes
        bindings_file "/etc/multipath_bindings"
}

2010/1/4 Bryn M. Reeves <bmr@redhat.com>:
> On Wed, 2009-12-30 at 12:52 +0100, brem belguebli wrote:
>> Hi,
>>
>> see man 5 lvm.conf there is an option called preferred_names which is
>> well explained
>>
>> It'll instruct lvm to use the preferred_names you configured in the
>> lvm.conf file if they exist
>>
>> ie : preferred_names = "/dev/mpath/" will use /dev/mpath/XXX instead
>> of /dev/mapper/XXX
>
> It's best not to use the symlinks in /dev/mpath - they are not always
> reliable. Use the device nodes created in /dev/mapper instead.
>
> Regards,
> Bryn.
>
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2010-01-04 13:17       ` brem belguebli
@ 2010-01-05 10:52         ` Simon Loewenthal/NL/Tele2
  2010-01-05 11:25           ` Simon Loewenthal/NL/Tele2
  0 siblings, 1 reply; 17+ messages in thread
From: Simon Loewenthal/NL/Tele2 @ 2010-01-05 10:52 UTC (permalink / raw)
  To: LVM general discussion and development


I just  this on a system with these in the lvm.conf:
    preferred_names = [ "^/dev/mapper/EMC_", "^/dev/[hs]d", "^/dev/cciss" ]
    filter = [ "r|/dev/.*/by-path/.*|", "r|/dev/.*/by-id/.*|",
"a|/dev/mapper/EMC_*|", "a|/dev/cciss/*|" , "r/.*/" ]


After a pvscan and vgscan I did a vgimport. Guess what: A vgimport of
the volume group ignored the filters and preferred devices and imported
the vg with these PVs (only one PV shown for brevity, but the rest are
similar ):

 PV Name               /dev/dm-16    
  PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
  PV Status             allocatable
  Total PE / Free PE    539 / 0

Unless, /dev/dm-16 is really some abstracted link back to a multipathed
device but I cannot work out this bit:
# ls -l /dev/mapper/
total 0
brw------- 1 root root 253, 17 Dec 30 15:11 EMC_0012
[SNIP]

# dmsetup ls
EMC_0103    (253, 13)
EMC_00FF    (253, 15)
EMC_0101    (253, 14)
EMC_00FD    (253, 16)
vg00-app052    (253, 3)
vg00-xen    (253, 2)
vg00-usr    (253, 0)
EMC_0113    (253, 4)
vg00-var    (253, 1)
EMC_0012    (253, 17)
EMC_010F    (253, 6)
EMC_0109    (253, 10)
EMC_0111    (253, 5)
EMC_010D    (253, 8)
EMC_0107    (253, 11)
EMC_010B    (253, 9)
EMC_0105    (253, 12)


The output of pvscan and vgscan follow:

*PVSCAN*
# pvscan -vv
      Setting global/locking_type to 1
      File-based locking selected.
      Setting global/locking_dir to /var/lock/lvm
    Wiping cache of LVM-capable devices
    Wiping internal VG cache
    Walking through all physical volumes
      /dev/cciss/c0d0: size is 286677120 sectors
      /dev/cciss/c0d0p1: size is 208782 sectors
      /dev/cciss/c0d0p1: size is 208782 sectors
      /dev/cciss/c0d0p1: No label detected
      /dev/cciss/c0d0p2: size is 4209030 sectors
      /dev/cciss/c0d0p2: size is 4209030 sectors
      /dev/cciss/c0d0p2: No label detected
      /dev/cciss/c0d0p3: size is 10490445 sectors
      /dev/cciss/c0d0p3: size is 10490445 sectors
      /dev/cciss/c0d0p3: No label detected
      /dev/cciss/c0d0p4: size is 271755540 sectors
      /dev/cciss/c0d0p4: size is 271755540 sectors
      /dev/cciss/c0d0p4: lvm2 label detected
      /dev/mapper/EMC_0113: size is 35358720 sectors
      /dev/mapper/EMC_0113: size is 35358720 sectors
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: size is 35358720 sectors
      /dev/mapper/EMC_0111: size is 35358720 sectors
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: size is 35358720 sectors
      /dev/mapper/EMC_010F: size is 35358720 sectors
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: size is 35358720 sectors
      /dev/mapper/EMC_010D: size is 35358720 sectors
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: size is 35358720 sectors
      /dev/mapper/EMC_010B: size is 35358720 sectors
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: size is 35358720 sectors
      /dev/mapper/EMC_0109: size is 35358720 sectors
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: size is 35358720 sectors
      /dev/mapper/EMC_0107: size is 35358720 sectors
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: size is 35358720 sectors
      /dev/mapper/EMC_0105: size is 35358720 sectors
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: size is 35358720 sectors
      /dev/mapper/EMC_0103: size is 35358720 sectors
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: size is 35358720 sectors
      /dev/mapper/EMC_0101: size is 35358720 sectors
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: size is 35358720 sectors
      /dev/mapper/EMC_00FF: size is 35358720 sectors
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: size is 35358720 sectors
      /dev/mapper/EMC_00FD: size is 35358720 sectors
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0012: size is 9600 sectors
      /dev/mapper/EMC_0012: size is 9600 sectors
      /dev/mapper/EMC_0012: No label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/cciss/c0d0p4: lvm2 label detected
      /dev/cciss/c0d0p4: lvm2 label detected
  PV /dev/mapper/EMC_0113    is in exported VG vg_mds [16.84 GB / 0    free]
  PV /dev/mapper/EMC_0111    is in exported VG vg_mds [16.84 GB / 0    free]
  PV /dev/mapper/EMC_010F    is in exported VG vg_mds [16.84 GB / 0    free]
  PV /dev/mapper/EMC_010D    is in exported VG vg_mds [16.84 GB / 0    free]
  PV /dev/mapper/EMC_010B    is in exported VG vg_mds [16.84 GB / 0    free]
  PV /dev/mapper/EMC_0109    is in exported VG vg_mds [16.84 GB / 0    free]
  PV /dev/mapper/EMC_0107    is in exported VG vg_mds [16.84 GB / 0    free]
  PV /dev/mapper/EMC_0105    is in exported VG vg_mds [16.84 GB / 0    free]
  PV /dev/mapper/EMC_0103    is in exported VG vg_mds [16.84 GB / 0    free]
  PV /dev/mapper/EMC_0101    is in exported VG vg_mds [16.84 GB / 0    free]
  PV /dev/mapper/EMC_00FF    is in exported VG vg_mds [16.84 GB / 0    free]
  PV /dev/mapper/EMC_00FD    is in exported VG vg_mds [16.84 GB / 0    free]
  PV /dev/cciss/c0d0p4      VG vg00     lvm2 [129.58 GB / 44.00 MB free]
  Total: 13 [331.71 GB] / in use: 13 [331.71 GB] / in no VG: 0 [0   ]

*VGSCAN
*# vgscan -vv
      Setting global/locking_type to 1
      File-based locking selected.
      Setting global/locking_dir to /var/lock/lvm
    Wiping cache of LVM-capable devices
    Wiping internal VG cache
  Reading all physical volumes.  This may take a while...
    Finding all volume groups
      /dev/cciss/c0d0: size is 286677120 sectors
      /dev/cciss/c0d0p1: size is 208782 sectors
      /dev/cciss/c0d0p1: size is 208782 sectors
      /dev/cciss/c0d0p1: No label detected
      /dev/cciss/c0d0p2: size is 4209030 sectors
      /dev/cciss/c0d0p2: size is 4209030 sectors
      /dev/cciss/c0d0p2: No label detected
      /dev/cciss/c0d0p3: size is 10490445 sectors
      /dev/cciss/c0d0p3: size is 10490445 sectors
      /dev/cciss/c0d0p3: No label detected
      /dev/cciss/c0d0p4: size is 271755540 sectors
      /dev/cciss/c0d0p4: size is 271755540 sectors
      /dev/cciss/c0d0p4: lvm2 label detected
      /dev/mapper/EMC_0113: size is 35358720 sectors
      /dev/mapper/EMC_0113: size is 35358720 sectors
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: size is 35358720 sectors
      /dev/mapper/EMC_0111: size is 35358720 sectors
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: size is 35358720 sectors
      /dev/mapper/EMC_010F: size is 35358720 sectors
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: size is 35358720 sectors
      /dev/mapper/EMC_010D: size is 35358720 sectors
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: size is 35358720 sectors
      /dev/mapper/EMC_010B: size is 35358720 sectors
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: size is 35358720 sectors
      /dev/mapper/EMC_0109: size is 35358720 sectors
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: size is 35358720 sectors
      /dev/mapper/EMC_0107: size is 35358720 sectors
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: size is 35358720 sectors
      /dev/mapper/EMC_0105: size is 35358720 sectors
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: size is 35358720 sectors
      /dev/mapper/EMC_0103: size is 35358720 sectors
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: size is 35358720 sectors
      /dev/mapper/EMC_0101: size is 35358720 sectors
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: size is 35358720 sectors
      /dev/mapper/EMC_00FF: size is 35358720 sectors
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: size is 35358720 sectors
      /dev/mapper/EMC_00FD: size is 35358720 sectors
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0012: size is 9600 sectors
      /dev/mapper/EMC_0012: size is 9600 sectors
      /dev/mapper/EMC_0012: No label detected
      Locking /var/lock/lvm/V_vg_mds RB
    Finding volume group "vg_mds"
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
      /dev/mapper/EMC_0113: lvm2 label detected
      /dev/mapper/EMC_0111: lvm2 label detected
      /dev/mapper/EMC_010F: lvm2 label detected
      /dev/mapper/EMC_010D: lvm2 label detected
      /dev/mapper/EMC_010B: lvm2 label detected
      /dev/mapper/EMC_0109: lvm2 label detected
      /dev/mapper/EMC_0107: lvm2 label detected
      /dev/mapper/EMC_0105: lvm2 label detected
      /dev/mapper/EMC_0103: lvm2 label detected
      /dev/mapper/EMC_0101: lvm2 label detected
      /dev/mapper/EMC_00FF: lvm2 label detected
      /dev/mapper/EMC_00FD: lvm2 label detected
  Found exported volume group "vg_mds" using metadata type lvm2
      Unlocking /var/lock/lvm/V_vg_mds
      Locking /var/lock/lvm/V_vg00 RB
    Finding volume group "vg00"
      /dev/cciss/c0d0p4: lvm2 label detected
      /dev/cciss/c0d0p4: lvm2 label detected
  Found volume group "vg00" using metadata type lvm2
      Unlocking /var/lock/lvm/V_vg00

brem belguebli wrote:
> Hi,
>
> Never had no problem with it.
>
> The only problem I've hit was due to the binding file being, by
> default, located in /var/lib/multipath, which is in my setup on a
> separate LV than /, during boot time the devices were not correctly
> created.
>
> Just had to switch the binding file to /etc and now no more problem.
>
> extract of my /etc/multipath.conf :
>
>
> defaults {
> ...
>         flush_on_last_del       yes
>         user_friendly_names     yes
>         bindings_file "/etc/multipath_bindings"
> }
>
> 2010/1/4 Bryn M. Reeves <bmr@redhat.com>:
>   
>> On Wed, 2009-12-30 at 12:52 +0100, brem belguebli wrote:
>>     
>>> Hi,
>>>
>>> see man 5 lvm.conf there is an option called preferred_names which is
>>> well explained
>>>
>>> It'll instruct lvm to use the preferred_names you configured in the
>>> lvm.conf file if they exist
>>>
>>> ie : preferred_names = "/dev/mpath/" will use /dev/mpath/XXX instead
>>> of /dev/mapper/XXX
>>>       
>> It's best not to use the symlinks in /dev/mpath - they are not always
>> reliable. Use the device nodes created in /dev/mapper instead.
>>
>> Regards,
>> Bryn.
>>
>>
>> _______________________________________________
>> linux-lvm mailing list
>> linux-lvm@redhat.com
>> https://www.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>
>>     
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>   

-- 
Simon Loewenthal/Tele2
GSM: +31 6 2000 5427

******** IMPORTANT NOTICE ********
Please repect the X-Reply to klunky.co.uk. PGP available 0xD86A5A17. 
S/MIME PKCS12 key available for Lotus Notes: Please ask me for it.
This e-mail (including any attachments) may contain information that is confidential or otherwise protected from disclosure and it is intended only for the addressees. If you are not the intended recipient, please note that any copying, distribution or other use of information contained in this e-mail (and its attachments) is not allowed. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message (including any attachments) from your system.
Please note that e-mail messages may contain computer viruses or other defects, may not be accurately replicated on other systems, or may be subject of unauthorized interception or other interference without the knowledge of sender or recipient. Tele2 only send and receive e-mails on the basis that Tele2 is not responsible for any such computer viruses, corruption or other interference or any consequences thereof.  It ought to be obvious that my views do not represent my employer's views.

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2010-01-05 10:52         ` Simon Loewenthal/NL/Tele2
@ 2010-01-05 11:25           ` Simon Loewenthal/NL/Tele2
  2010-01-05 16:12             ` Simon Loewenthal/NL/Tele2
  0 siblings, 1 reply; 17+ messages in thread
From: Simon Loewenthal/NL/Tele2 @ 2010-01-05 11:25 UTC (permalink / raw)
  Cc: LVM general discussion and development

Update:

I modified the filter to read:
filter = [ "r|/dev/.*/by-path/.*|", "r|/dev/.*/by-id/.*|",
"r|/dev/dm-*|" , "a|/dev/mapper/EMC*|", "a|/dev/cciss/*|" , "r/.*/" ]

and this made no difference.

What did work was to turn off the cache and delete the .cache file:
 write_cache_state = 0

Then the discs were brought in as so:
 PV Name               /dev/mapper/EMC_00FD    
  PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
  PV Status             allocatable
  Total PE / Free PE    539 / 0


Howevr, as soon as I activated the cache:
write_cache_state = 1
then the discs in the volume group magically reverted to

 PV Name               /dev/dm-16    
  PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
  PV Status             allocatable
  Total PE / Free PE    539 / 0


Any clues?

Simon Loewenthal/NL/Tele2 wrote:
> I just  this on a system with these in the lvm.conf:
>     preferred_names = [ "^/dev/mapper/EMC_", "^/dev/[hs]d", "^/dev/cciss" ]
>     filter = [ "r|/dev/.*/by-path/.*|", "r|/dev/.*/by-id/.*|",
> "a|/dev/mapper/EMC_*|", "a|/dev/cciss/*|" , "r/.*/" ]
>
>
> After a pvscan and vgscan I did a vgimport. Guess what: A vgimport of
> the volume group ignored the filters and preferred devices and imported
> the vg with these PVs (only one PV shown for brevity, but the rest are
> similar ):
>
>  PV Name               /dev/dm-16    
>   PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>
> Unless, /dev/dm-16 is really some abstracted link back to a multipathed
> device but I cannot work out this bit:
> # ls -l /dev/mapper/
> total 0
> brw------- 1 root root 253, 17 Dec 30 15:11 EMC_0012
> [SNIP]
>
> # dmsetup ls
> EMC_0103    (253, 13)
> EMC_00FF    (253, 15)
> EMC_0101    (253, 14)
> EMC_00FD    (253, 16)
> vg00-app052    (253, 3)
> vg00-xen    (253, 2)
> vg00-usr    (253, 0)
> EMC_0113    (253, 4)
> vg00-var    (253, 1)
> EMC_0012    (253, 17)
> EMC_010F    (253, 6)
> EMC_0109    (253, 10)
> EMC_0111    (253, 5)
> EMC_010D    (253, 8)
> EMC_0107    (253, 11)
> EMC_010B    (253, 9)
> EMC_0105    (253, 12)
>
>
> The output of pvscan and vgscan follow:
>
> *PVSCAN*
> # pvscan -vv
>       Setting global/locking_type to 1
>       File-based locking selected.
>       Setting global/locking_dir to /var/lock/lvm
>     Wiping cache of LVM-capable devices
>     Wiping internal VG cache
>     Walking through all physical volumes
>       /dev/cciss/c0d0: size is 286677120 sectors
>       /dev/cciss/c0d0p1: size is 208782 sectors
>       /dev/cciss/c0d0p1: size is 208782 sectors
>       /dev/cciss/c0d0p1: No label detected
>       /dev/cciss/c0d0p2: size is 4209030 sectors
>       /dev/cciss/c0d0p2: size is 4209030 sectors
>       /dev/cciss/c0d0p2: No label detected
>       /dev/cciss/c0d0p3: size is 10490445 sectors
>       /dev/cciss/c0d0p3: size is 10490445 sectors
>       /dev/cciss/c0d0p3: No label detected
>       /dev/cciss/c0d0p4: size is 271755540 sectors
>       /dev/cciss/c0d0p4: size is 271755540 sectors
>       /dev/cciss/c0d0p4: lvm2 label detected
>       /dev/mapper/EMC_0113: size is 35358720 sectors
>       /dev/mapper/EMC_0113: size is 35358720 sectors
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: size is 35358720 sectors
>       /dev/mapper/EMC_0111: size is 35358720 sectors
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: size is 35358720 sectors
>       /dev/mapper/EMC_010F: size is 35358720 sectors
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: size is 35358720 sectors
>       /dev/mapper/EMC_010D: size is 35358720 sectors
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: size is 35358720 sectors
>       /dev/mapper/EMC_010B: size is 35358720 sectors
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: size is 35358720 sectors
>       /dev/mapper/EMC_0109: size is 35358720 sectors
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: size is 35358720 sectors
>       /dev/mapper/EMC_0107: size is 35358720 sectors
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: size is 35358720 sectors
>       /dev/mapper/EMC_0105: size is 35358720 sectors
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: size is 35358720 sectors
>       /dev/mapper/EMC_0103: size is 35358720 sectors
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: size is 35358720 sectors
>       /dev/mapper/EMC_0101: size is 35358720 sectors
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: size is 35358720 sectors
>       /dev/mapper/EMC_00FF: size is 35358720 sectors
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: size is 35358720 sectors
>       /dev/mapper/EMC_00FD: size is 35358720 sectors
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0012: size is 9600 sectors
>       /dev/mapper/EMC_0012: size is 9600 sectors
>       /dev/mapper/EMC_0012: No label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/cciss/c0d0p4: lvm2 label detected
>       /dev/cciss/c0d0p4: lvm2 label detected
>   PV /dev/mapper/EMC_0113    is in exported VG vg_mds [16.84 GB / 0    free]
>   PV /dev/mapper/EMC_0111    is in exported VG vg_mds [16.84 GB / 0    free]
>   PV /dev/mapper/EMC_010F    is in exported VG vg_mds [16.84 GB / 0    free]
>   PV /dev/mapper/EMC_010D    is in exported VG vg_mds [16.84 GB / 0    free]
>   PV /dev/mapper/EMC_010B    is in exported VG vg_mds [16.84 GB / 0    free]
>   PV /dev/mapper/EMC_0109    is in exported VG vg_mds [16.84 GB / 0    free]
>   PV /dev/mapper/EMC_0107    is in exported VG vg_mds [16.84 GB / 0    free]
>   PV /dev/mapper/EMC_0105    is in exported VG vg_mds [16.84 GB / 0    free]
>   PV /dev/mapper/EMC_0103    is in exported VG vg_mds [16.84 GB / 0    free]
>   PV /dev/mapper/EMC_0101    is in exported VG vg_mds [16.84 GB / 0    free]
>   PV /dev/mapper/EMC_00FF    is in exported VG vg_mds [16.84 GB / 0    free]
>   PV /dev/mapper/EMC_00FD    is in exported VG vg_mds [16.84 GB / 0    free]
>   PV /dev/cciss/c0d0p4      VG vg00     lvm2 [129.58 GB / 44.00 MB free]
>   Total: 13 [331.71 GB] / in use: 13 [331.71 GB] / in no VG: 0 [0   ]
>
> *VGSCAN
> *# vgscan -vv
>       Setting global/locking_type to 1
>       File-based locking selected.
>       Setting global/locking_dir to /var/lock/lvm
>     Wiping cache of LVM-capable devices
>     Wiping internal VG cache
>   Reading all physical volumes.  This may take a while...
>     Finding all volume groups
>       /dev/cciss/c0d0: size is 286677120 sectors
>       /dev/cciss/c0d0p1: size is 208782 sectors
>       /dev/cciss/c0d0p1: size is 208782 sectors
>       /dev/cciss/c0d0p1: No label detected
>       /dev/cciss/c0d0p2: size is 4209030 sectors
>       /dev/cciss/c0d0p2: size is 4209030 sectors
>       /dev/cciss/c0d0p2: No label detected
>       /dev/cciss/c0d0p3: size is 10490445 sectors
>       /dev/cciss/c0d0p3: size is 10490445 sectors
>       /dev/cciss/c0d0p3: No label detected
>       /dev/cciss/c0d0p4: size is 271755540 sectors
>       /dev/cciss/c0d0p4: size is 271755540 sectors
>       /dev/cciss/c0d0p4: lvm2 label detected
>       /dev/mapper/EMC_0113: size is 35358720 sectors
>       /dev/mapper/EMC_0113: size is 35358720 sectors
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: size is 35358720 sectors
>       /dev/mapper/EMC_0111: size is 35358720 sectors
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: size is 35358720 sectors
>       /dev/mapper/EMC_010F: size is 35358720 sectors
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: size is 35358720 sectors
>       /dev/mapper/EMC_010D: size is 35358720 sectors
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: size is 35358720 sectors
>       /dev/mapper/EMC_010B: size is 35358720 sectors
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: size is 35358720 sectors
>       /dev/mapper/EMC_0109: size is 35358720 sectors
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: size is 35358720 sectors
>       /dev/mapper/EMC_0107: size is 35358720 sectors
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: size is 35358720 sectors
>       /dev/mapper/EMC_0105: size is 35358720 sectors
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: size is 35358720 sectors
>       /dev/mapper/EMC_0103: size is 35358720 sectors
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: size is 35358720 sectors
>       /dev/mapper/EMC_0101: size is 35358720 sectors
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: size is 35358720 sectors
>       /dev/mapper/EMC_00FF: size is 35358720 sectors
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: size is 35358720 sectors
>       /dev/mapper/EMC_00FD: size is 35358720 sectors
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0012: size is 9600 sectors
>       /dev/mapper/EMC_0012: size is 9600 sectors
>       /dev/mapper/EMC_0012: No label detected
>       Locking /var/lock/lvm/V_vg_mds RB
>     Finding volume group "vg_mds"
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>       /dev/mapper/EMC_0113: lvm2 label detected
>       /dev/mapper/EMC_0111: lvm2 label detected
>       /dev/mapper/EMC_010F: lvm2 label detected
>       /dev/mapper/EMC_010D: lvm2 label detected
>       /dev/mapper/EMC_010B: lvm2 label detected
>       /dev/mapper/EMC_0109: lvm2 label detected
>       /dev/mapper/EMC_0107: lvm2 label detected
>       /dev/mapper/EMC_0105: lvm2 label detected
>       /dev/mapper/EMC_0103: lvm2 label detected
>       /dev/mapper/EMC_0101: lvm2 label detected
>       /dev/mapper/EMC_00FF: lvm2 label detected
>       /dev/mapper/EMC_00FD: lvm2 label detected
>   Found exported volume group "vg_mds" using metadata type lvm2
>       Unlocking /var/lock/lvm/V_vg_mds
>       Locking /var/lock/lvm/V_vg00 RB
>     Finding volume group "vg00"
>       /dev/cciss/c0d0p4: lvm2 label detected
>       /dev/cciss/c0d0p4: lvm2 label detected
>   Found volume group "vg00" using metadata type lvm2
>       Unlocking /var/lock/lvm/V_vg00
>
> brem belguebli wrote:
>   
>> Hi,
>>
>> Never had no problem with it.
>>
>> The only problem I've hit was due to the binding file being, by
>> default, located in /var/lib/multipath, which is in my setup on a
>> separate LV than /, during boot time the devices were not correctly
>> created.
>>
>> Just had to switch the binding file to /etc and now no more problem.
>>
>> extract of my /etc/multipath.conf :
>>
>>
>> defaults {
>> ...
>>         flush_on_last_del       yes
>>         user_friendly_names     yes
>>         bindings_file "/etc/multipath_bindings"
>> }
>>
>> 2010/1/4 Bryn M. Reeves <bmr@redhat.com>:
>>   
>>     
>>> On Wed, 2009-12-30 at 12:52 +0100, brem belguebli wrote:
>>>     
>>>       
>>>> Hi,
>>>>
>>>> see man 5 lvm.conf there is an option called preferred_names which is
>>>> well explained
>>>>
>>>> It'll instruct lvm to use the preferred_names you configured in the
>>>> lvm.conf file if they exist
>>>>
>>>> ie : preferred_names = "/dev/mpath/" will use /dev/mpath/XXX instead
>>>> of /dev/mapper/XXX
>>>>       
>>>>         
>>> It's best not to use the symlinks in /dev/mpath - they are not always
>>> reliable. Use the device nodes created in /dev/mapper instead.
>>>
>>> Regards,
>>> Bryn.
>>>
>>>
>>> _______________________________________________
>>> linux-lvm mailing list
>>> linux-lvm@redhat.com
>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>
>>>     
>>>       
>> _______________________________________________
>> linux-lvm mailing list
>> linux-lvm@redhat.com
>> https://www.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>   
>>     
>
>   

-- 
Simon Loewenthal/Tele2
GSM: +31 6 2000 5427

******** IMPORTANT NOTICE ********
Please repect the X-Reply to klunky.co.uk. PGP available 0xD86A5A17. 
S/MIME PKCS12 key available for Lotus Notes: Please ask me for it.
This e-mail (including any attachments) may contain information that is confidential or otherwise protected from disclosure and it is intended only for the addressees. If you are not the intended recipient, please note that any copying, distribution or other use of information contained in this e-mail (and its attachments) is not allowed. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message (including any attachments) from your system.
Please note that e-mail messages may contain computer viruses or other defects, may not be accurately replicated on other systems, or may be subject of unauthorized interception or other interference without the knowledge of sender or recipient. Tele2 only send and receive e-mails on the basis that Tele2 is not responsible for any such computer viruses, corruption or other interference or any consequences thereof.  It ought to be obvious that my views do not represent my employer's views.

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2010-01-05 11:25           ` Simon Loewenthal/NL/Tele2
@ 2010-01-05 16:12             ` Simon Loewenthal/NL/Tele2
  2010-01-11 14:12               ` Simon Loewenthal/NL/Tele2
  0 siblings, 1 reply; 17+ messages in thread
From: Simon Loewenthal/NL/Tele2 @ 2010-01-05 16:12 UTC (permalink / raw)
  To: LVM general discussion and development

More info:

I thought for a moment that LVM might cache the devices somewhere other
than in the cache but am unsure as per output from strace :-

# grep -i cach typescript.*
typescript.pvscan:open("/etc/ld.so.cache", O_RDONLY)      = 3
typescript.pvscan:open("/usr/lib64/gconv/gconv-modules.cache", O_RDONLY) = 3
typescript.pvscan:stat("/etc/lvm/.cache", 0x7fff2193b6d0) = -1 ENOENT
(No such file or directory)
typescript.vgscan:open("/etc/ld.so.cache", O_RDONLY)      = 3
typescript.vgscan:open("/usr/lib64/gconv/gconv-modules.cache", O_RDONLY) = 3
typescript.vgscan:stat("/etc/lvm/.cache", 0x7fff8d6ad440) = -1 ENOENT
(No such file or directory)



Simon Loewenthal/NL/Tele2 wrote:
> Update:
>
> I modified the filter to read:
> filter = [ "r|/dev/.*/by-path/.*|", "r|/dev/.*/by-id/.*|",
> "r|/dev/dm-*|" , "a|/dev/mapper/EMC*|", "a|/dev/cciss/*|" , "r/.*/" ]
>
> and this made no difference.
>
> What did work was to turn off the cache and delete the .cache file:
>  write_cache_state = 0
>
> Then the discs were brought in as so:
>  PV Name               /dev/mapper/EMC_00FD    
>   PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>
>
> Howevr, as soon as I activated the cache:
> write_cache_state = 1
> then the discs in the volume group magically reverted to
>
>  PV Name               /dev/dm-16    
>   PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
>   PV Status             allocatable
>   Total PE / Free PE    539 / 0
>
>
> Any clues?
>
> Simon Loewenthal/NL/Tele2 wrote:
>   
>> I just  this on a system with these in the lvm.conf:
>>     preferred_names = [ "^/dev/mapper/EMC_", "^/dev/[hs]d", "^/dev/cciss" ]
>>     filter = [ "r|/dev/.*/by-path/.*|", "r|/dev/.*/by-id/.*|",
>> "a|/dev/mapper/EMC_*|", "a|/dev/cciss/*|" , "r/.*/" ]
>>
>>
>> After a pvscan and vgscan I did a vgimport. Guess what: A vgimport of
>> the volume group ignored the filters and preferred devices and imported
>> the vg with these PVs (only one PV shown for brevity, but the rest are
>> similar ):
>>
>>  PV Name               /dev/dm-16    
>>   PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
>>   PV Status             allocatable
>>   Total PE / Free PE    539 / 0
>>
>> Unless, /dev/dm-16 is really some abstracted link back to a multipathed
>> device but I cannot work out this bit:
>> # ls -l /dev/mapper/
>> total 0
>> brw------- 1 root root 253, 17 Dec 30 15:11 EMC_0012
>> [SNIP]
>>
>> # dmsetup ls
>> EMC_0103    (253, 13)
>> EMC_00FF    (253, 15)
>> EMC_0101    (253, 14)
>> EMC_00FD    (253, 16)
>> vg00-app052    (253, 3)
>> vg00-xen    (253, 2)
>> vg00-usr    (253, 0)
>> EMC_0113    (253, 4)
>> vg00-var    (253, 1)
>> EMC_0012    (253, 17)
>> EMC_010F    (253, 6)
>> EMC_0109    (253, 10)
>> EMC_0111    (253, 5)
>> EMC_010D    (253, 8)
>> EMC_0107    (253, 11)
>> EMC_010B    (253, 9)
>> EMC_0105    (253, 12)
>>
>>
>> The output of pvscan and vgscan follow:
>>
>> *PVSCAN*
>> # pvscan -vv
>>       Setting global/locking_type to 1
>>       File-based locking selected.
>>       Setting global/locking_dir to /var/lock/lvm
>>     Wiping cache of LVM-capable devices
>>     Wiping internal VG cache
>>     Walking through all physical volumes
>>       /dev/cciss/c0d0: size is 286677120 sectors
>>       /dev/cciss/c0d0p1: size is 208782 sectors
>>       /dev/cciss/c0d0p1: size is 208782 sectors
>>       /dev/cciss/c0d0p1: No label detected
>>       /dev/cciss/c0d0p2: size is 4209030 sectors
>>       /dev/cciss/c0d0p2: size is 4209030 sectors
>>       /dev/cciss/c0d0p2: No label detected
>>       /dev/cciss/c0d0p3: size is 10490445 sectors
>>       /dev/cciss/c0d0p3: size is 10490445 sectors
>>       /dev/cciss/c0d0p3: No label detected
>>       /dev/cciss/c0d0p4: size is 271755540 sectors
>>       /dev/cciss/c0d0p4: size is 271755540 sectors
>>       /dev/cciss/c0d0p4: lvm2 label detected
>>       /dev/mapper/EMC_0113: size is 35358720 sectors
>>       /dev/mapper/EMC_0113: size is 35358720 sectors
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: size is 35358720 sectors
>>       /dev/mapper/EMC_0111: size is 35358720 sectors
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: size is 35358720 sectors
>>       /dev/mapper/EMC_010F: size is 35358720 sectors
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: size is 35358720 sectors
>>       /dev/mapper/EMC_010D: size is 35358720 sectors
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: size is 35358720 sectors
>>       /dev/mapper/EMC_010B: size is 35358720 sectors
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: size is 35358720 sectors
>>       /dev/mapper/EMC_0109: size is 35358720 sectors
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: size is 35358720 sectors
>>       /dev/mapper/EMC_0107: size is 35358720 sectors
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: size is 35358720 sectors
>>       /dev/mapper/EMC_0105: size is 35358720 sectors
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: size is 35358720 sectors
>>       /dev/mapper/EMC_0103: size is 35358720 sectors
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: size is 35358720 sectors
>>       /dev/mapper/EMC_0101: size is 35358720 sectors
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: size is 35358720 sectors
>>       /dev/mapper/EMC_00FF: size is 35358720 sectors
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: size is 35358720 sectors
>>       /dev/mapper/EMC_00FD: size is 35358720 sectors
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0012: size is 9600 sectors
>>       /dev/mapper/EMC_0012: size is 9600 sectors
>>       /dev/mapper/EMC_0012: No label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/cciss/c0d0p4: lvm2 label detected
>>       /dev/cciss/c0d0p4: lvm2 label detected
>>   PV /dev/mapper/EMC_0113    is in exported VG vg_mds [16.84 GB / 0    free]
>>   PV /dev/mapper/EMC_0111    is in exported VG vg_mds [16.84 GB / 0    free]
>>   PV /dev/mapper/EMC_010F    is in exported VG vg_mds [16.84 GB / 0    free]
>>   PV /dev/mapper/EMC_010D    is in exported VG vg_mds [16.84 GB / 0    free]
>>   PV /dev/mapper/EMC_010B    is in exported VG vg_mds [16.84 GB / 0    free]
>>   PV /dev/mapper/EMC_0109    is in exported VG vg_mds [16.84 GB / 0    free]
>>   PV /dev/mapper/EMC_0107    is in exported VG vg_mds [16.84 GB / 0    free]
>>   PV /dev/mapper/EMC_0105    is in exported VG vg_mds [16.84 GB / 0    free]
>>   PV /dev/mapper/EMC_0103    is in exported VG vg_mds [16.84 GB / 0    free]
>>   PV /dev/mapper/EMC_0101    is in exported VG vg_mds [16.84 GB / 0    free]
>>   PV /dev/mapper/EMC_00FF    is in exported VG vg_mds [16.84 GB / 0    free]
>>   PV /dev/mapper/EMC_00FD    is in exported VG vg_mds [16.84 GB / 0    free]
>>   PV /dev/cciss/c0d0p4      VG vg00     lvm2 [129.58 GB / 44.00 MB free]
>>   Total: 13 [331.71 GB] / in use: 13 [331.71 GB] / in no VG: 0 [0   ]
>>
>> *VGSCAN
>> *# vgscan -vv
>>       Setting global/locking_type to 1
>>       File-based locking selected.
>>       Setting global/locking_dir to /var/lock/lvm
>>     Wiping cache of LVM-capable devices
>>     Wiping internal VG cache
>>   Reading all physical volumes.  This may take a while...
>>     Finding all volume groups
>>       /dev/cciss/c0d0: size is 286677120 sectors
>>       /dev/cciss/c0d0p1: size is 208782 sectors
>>       /dev/cciss/c0d0p1: size is 208782 sectors
>>       /dev/cciss/c0d0p1: No label detected
>>       /dev/cciss/c0d0p2: size is 4209030 sectors
>>       /dev/cciss/c0d0p2: size is 4209030 sectors
>>       /dev/cciss/c0d0p2: No label detected
>>       /dev/cciss/c0d0p3: size is 10490445 sectors
>>       /dev/cciss/c0d0p3: size is 10490445 sectors
>>       /dev/cciss/c0d0p3: No label detected
>>       /dev/cciss/c0d0p4: size is 271755540 sectors
>>       /dev/cciss/c0d0p4: size is 271755540 sectors
>>       /dev/cciss/c0d0p4: lvm2 label detected
>>       /dev/mapper/EMC_0113: size is 35358720 sectors
>>       /dev/mapper/EMC_0113: size is 35358720 sectors
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: size is 35358720 sectors
>>       /dev/mapper/EMC_0111: size is 35358720 sectors
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: size is 35358720 sectors
>>       /dev/mapper/EMC_010F: size is 35358720 sectors
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: size is 35358720 sectors
>>       /dev/mapper/EMC_010D: size is 35358720 sectors
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: size is 35358720 sectors
>>       /dev/mapper/EMC_010B: size is 35358720 sectors
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: size is 35358720 sectors
>>       /dev/mapper/EMC_0109: size is 35358720 sectors
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: size is 35358720 sectors
>>       /dev/mapper/EMC_0107: size is 35358720 sectors
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: size is 35358720 sectors
>>       /dev/mapper/EMC_0105: size is 35358720 sectors
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: size is 35358720 sectors
>>       /dev/mapper/EMC_0103: size is 35358720 sectors
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: size is 35358720 sectors
>>       /dev/mapper/EMC_0101: size is 35358720 sectors
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: size is 35358720 sectors
>>       /dev/mapper/EMC_00FF: size is 35358720 sectors
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: size is 35358720 sectors
>>       /dev/mapper/EMC_00FD: size is 35358720 sectors
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0012: size is 9600 sectors
>>       /dev/mapper/EMC_0012: size is 9600 sectors
>>       /dev/mapper/EMC_0012: No label detected
>>       Locking /var/lock/lvm/V_vg_mds RB
>>     Finding volume group "vg_mds"
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>       /dev/mapper/EMC_0113: lvm2 label detected
>>       /dev/mapper/EMC_0111: lvm2 label detected
>>       /dev/mapper/EMC_010F: lvm2 label detected
>>       /dev/mapper/EMC_010D: lvm2 label detected
>>       /dev/mapper/EMC_010B: lvm2 label detected
>>       /dev/mapper/EMC_0109: lvm2 label detected
>>       /dev/mapper/EMC_0107: lvm2 label detected
>>       /dev/mapper/EMC_0105: lvm2 label detected
>>       /dev/mapper/EMC_0103: lvm2 label detected
>>       /dev/mapper/EMC_0101: lvm2 label detected
>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>   Found exported volume group "vg_mds" using metadata type lvm2
>>       Unlocking /var/lock/lvm/V_vg_mds
>>       Locking /var/lock/lvm/V_vg00 RB
>>     Finding volume group "vg00"
>>       /dev/cciss/c0d0p4: lvm2 label detected
>>       /dev/cciss/c0d0p4: lvm2 label detected
>>   Found volume group "vg00" using metadata type lvm2
>>       Unlocking /var/lock/lvm/V_vg00
>>
>> brem belguebli wrote:
>>   
>>     
>>> Hi,
>>>
>>> Never had no problem with it.
>>>
>>> The only problem I've hit was due to the binding file being, by
>>> default, located in /var/lib/multipath, which is in my setup on a
>>> separate LV than /, during boot time the devices were not correctly
>>> created.
>>>
>>> Just had to switch the binding file to /etc and now no more problem.
>>>
>>> extract of my /etc/multipath.conf :
>>>
>>>
>>> defaults {
>>> ...
>>>         flush_on_last_del       yes
>>>         user_friendly_names     yes
>>>         bindings_file "/etc/multipath_bindings"
>>> }
>>>
>>> 2010/1/4 Bryn M. Reeves <bmr@redhat.com>:
>>>   
>>>     
>>>       
>>>> On Wed, 2009-12-30 at 12:52 +0100, brem belguebli wrote:
>>>>     
>>>>       
>>>>         
>>>>> Hi,
>>>>>
>>>>> see man 5 lvm.conf there is an option called preferred_names which is
>>>>> well explained
>>>>>
>>>>> It'll instruct lvm to use the preferred_names you configured in the
>>>>> lvm.conf file if they exist
>>>>>
>>>>> ie : preferred_names = "/dev/mpath/" will use /dev/mpath/XXX instead
>>>>> of /dev/mapper/XXX
>>>>>       
>>>>>         
>>>>>           
>>>> It's best not to use the symlinks in /dev/mpath - they are not always
>>>> reliable. Use the device nodes created in /dev/mapper instead.
>>>>
>>>> Regards,
>>>> Bryn.
>>>>
>>>>
>>>> _______________________________________________
>>>> linux-lvm mailing list
>>>> linux-lvm@redhat.com
>>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>>
>>>>     
>>>>       
>>>>         
>>> _______________________________________________
>>> linux-lvm mailing list
>>> linux-lvm@redhat.com
>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>   
>>>     
>>>       
>>   
>>     
>
>   

-- 
Simon Loewenthal/Tele2
GSM: +31 6 2000 5427

******** IMPORTANT NOTICE ********
Please repect the X-Reply to klunky.co.uk. PGP available 0xD86A5A17. 
S/MIME PKCS12 key available for Lotus Notes: Please ask me for it.
This e-mail (including any attachments) may contain information that is confidential or otherwise protected from disclosure and it is intended only for the addressees. If you are not the intended recipient, please note that any copying, distribution or other use of information contained in this e-mail (and its attachments) is not allowed. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message (including any attachments) from your system.
Please note that e-mail messages may contain computer viruses or other defects, may not be accurately replicated on other systems, or may be subject of unauthorized interception or other interference without the knowledge of sender or recipient. Tele2 only send and receive e-mails on the basis that Tele2 is not responsible for any such computer viruses, corruption or other interference or any consequences thereof.  It ought to be obvious that my views do not represent my employer's views.

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2010-01-05 16:12             ` Simon Loewenthal/NL/Tele2
@ 2010-01-11 14:12               ` Simon Loewenthal/NL/Tele2
  2010-01-11 15:18                 ` Eugene Vilensky
  0 siblings, 1 reply; 17+ messages in thread
From: Simon Loewenthal/NL/Tele2 @ 2010-01-11 14:12 UTC (permalink / raw)
  To: LVM general discussion and development

Hi,

    Did anyone ever know why this happens?

With write_cache_state = 0 the PV Name displays the multipathed discs
but with write_cache_state = 1 then the PV Name displays the dm disc
name eg.

This:

PV Name               /dev/mapper/EMC_00FD   

verses:

PV Name               /dev/dm-16  

How do I really know LVM is really using the mutlipath other than
disabling one of the ports on the switch, which I don't wish to do on a
production box.

Regards, S.

Simon Loewenthal/NL/Tele2 wrote:
> More info:
>
> I thought for a moment that LVM might cache the devices somewhere other
> than in the cache but am unsure as per output from strace :-
>
> # grep -i cach typescript.*
> typescript.pvscan:open("/etc/ld.so.cache", O_RDONLY)      = 3
> typescript.pvscan:open("/usr/lib64/gconv/gconv-modules.cache", O_RDONLY) = 3
> typescript.pvscan:stat("/etc/lvm/.cache", 0x7fff2193b6d0) = -1 ENOENT
> (No such file or directory)
> typescript.vgscan:open("/etc/ld.so.cache", O_RDONLY)      = 3
> typescript.vgscan:open("/usr/lib64/gconv/gconv-modules.cache", O_RDONLY) = 3
> typescript.vgscan:stat("/etc/lvm/.cache", 0x7fff8d6ad440) = -1 ENOENT
> (No such file or directory)
>
>
>
> Simon Loewenthal/NL/Tele2 wrote:
>   
>> Update:
>>
>> I modified the filter to read:
>> filter = [ "r|/dev/.*/by-path/.*|", "r|/dev/.*/by-id/.*|",
>> "r|/dev/dm-*|" , "a|/dev/mapper/EMC*|", "a|/dev/cciss/*|" , "r/.*/" ]
>>
>> and this made no difference.
>>
>> What did work was to turn off the cache and delete the .cache file:
>>  write_cache_state = 0
>>
>> Then the discs were brought in as so:
>>  PV Name               /dev/mapper/EMC_00FD    
>>   PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
>>   PV Status             allocatable
>>   Total PE / Free PE    539 / 0
>>
>>
>> Howevr, as soon as I activated the cache:
>> write_cache_state = 1
>> then the discs in the volume group magically reverted to
>>
>>  PV Name               /dev/dm-16    
>>   PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
>>   PV Status             allocatable
>>   Total PE / Free PE    539 / 0
>>
>>
>> Any clues?
>>
>> Simon Loewenthal/NL/Tele2 wrote:
>>   
>>     
>>> I just  this on a system with these in the lvm.conf:
>>>     preferred_names = [ "^/dev/mapper/EMC_", "^/dev/[hs]d", "^/dev/cciss" ]
>>>     filter = [ "r|/dev/.*/by-path/.*|", "r|/dev/.*/by-id/.*|",
>>> "a|/dev/mapper/EMC_*|", "a|/dev/cciss/*|" , "r/.*/" ]
>>>
>>>
>>> After a pvscan and vgscan I did a vgimport. Guess what: A vgimport of
>>> the volume group ignored the filters and preferred devices and imported
>>> the vg with these PVs (only one PV shown for brevity, but the rest are
>>> similar ):
>>>
>>>  PV Name               /dev/dm-16    
>>>   PV UUID               ctz8rd-ew58-0pU8-FssR-x9pR-KSA9-mI4flw
>>>   PV Status             allocatable
>>>   Total PE / Free PE    539 / 0
>>>
>>> Unless, /dev/dm-16 is really some abstracted link back to a multipathed
>>> device but I cannot work out this bit:
>>> # ls -l /dev/mapper/
>>> total 0
>>> brw------- 1 root root 253, 17 Dec 30 15:11 EMC_0012
>>> [SNIP]
>>>
>>> # dmsetup ls
>>> EMC_0103    (253, 13)
>>> EMC_00FF    (253, 15)
>>> EMC_0101    (253, 14)
>>> EMC_00FD    (253, 16)
>>> vg00-app052    (253, 3)
>>> vg00-xen    (253, 2)
>>> vg00-usr    (253, 0)
>>> EMC_0113    (253, 4)
>>> vg00-var    (253, 1)
>>> EMC_0012    (253, 17)
>>> EMC_010F    (253, 6)
>>> EMC_0109    (253, 10)
>>> EMC_0111    (253, 5)
>>> EMC_010D    (253, 8)
>>> EMC_0107    (253, 11)
>>> EMC_010B    (253, 9)
>>> EMC_0105    (253, 12)
>>>
>>>
>>> The output of pvscan and vgscan follow:
>>>
>>> *PVSCAN*
>>> # pvscan -vv
>>>       Setting global/locking_type to 1
>>>       File-based locking selected.
>>>       Setting global/locking_dir to /var/lock/lvm
>>>     Wiping cache of LVM-capable devices
>>>     Wiping internal VG cache
>>>     Walking through all physical volumes
>>>       /dev/cciss/c0d0: size is 286677120 sectors
>>>       /dev/cciss/c0d0p1: size is 208782 sectors
>>>       /dev/cciss/c0d0p1: size is 208782 sectors
>>>       /dev/cciss/c0d0p1: No label detected
>>>       /dev/cciss/c0d0p2: size is 4209030 sectors
>>>       /dev/cciss/c0d0p2: size is 4209030 sectors
>>>       /dev/cciss/c0d0p2: No label detected
>>>       /dev/cciss/c0d0p3: size is 10490445 sectors
>>>       /dev/cciss/c0d0p3: size is 10490445 sectors
>>>       /dev/cciss/c0d0p3: No label detected
>>>       /dev/cciss/c0d0p4: size is 271755540 sectors
>>>       /dev/cciss/c0d0p4: size is 271755540 sectors
>>>       /dev/cciss/c0d0p4: lvm2 label detected
>>>       /dev/mapper/EMC_0113: size is 35358720 sectors
>>>       /dev/mapper/EMC_0113: size is 35358720 sectors
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: size is 35358720 sectors
>>>       /dev/mapper/EMC_0111: size is 35358720 sectors
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: size is 35358720 sectors
>>>       /dev/mapper/EMC_010F: size is 35358720 sectors
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: size is 35358720 sectors
>>>       /dev/mapper/EMC_010D: size is 35358720 sectors
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: size is 35358720 sectors
>>>       /dev/mapper/EMC_010B: size is 35358720 sectors
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: size is 35358720 sectors
>>>       /dev/mapper/EMC_0109: size is 35358720 sectors
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: size is 35358720 sectors
>>>       /dev/mapper/EMC_0107: size is 35358720 sectors
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: size is 35358720 sectors
>>>       /dev/mapper/EMC_0105: size is 35358720 sectors
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: size is 35358720 sectors
>>>       /dev/mapper/EMC_0103: size is 35358720 sectors
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: size is 35358720 sectors
>>>       /dev/mapper/EMC_0101: size is 35358720 sectors
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: size is 35358720 sectors
>>>       /dev/mapper/EMC_00FF: size is 35358720 sectors
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: size is 35358720 sectors
>>>       /dev/mapper/EMC_00FD: size is 35358720 sectors
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0012: size is 9600 sectors
>>>       /dev/mapper/EMC_0012: size is 9600 sectors
>>>       /dev/mapper/EMC_0012: No label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/cciss/c0d0p4: lvm2 label detected
>>>       /dev/cciss/c0d0p4: lvm2 label detected
>>>   PV /dev/mapper/EMC_0113    is in exported VG vg_mds [16.84 GB / 0    free]
>>>   PV /dev/mapper/EMC_0111    is in exported VG vg_mds [16.84 GB / 0    free]
>>>   PV /dev/mapper/EMC_010F    is in exported VG vg_mds [16.84 GB / 0    free]
>>>   PV /dev/mapper/EMC_010D    is in exported VG vg_mds [16.84 GB / 0    free]
>>>   PV /dev/mapper/EMC_010B    is in exported VG vg_mds [16.84 GB / 0    free]
>>>   PV /dev/mapper/EMC_0109    is in exported VG vg_mds [16.84 GB / 0    free]
>>>   PV /dev/mapper/EMC_0107    is in exported VG vg_mds [16.84 GB / 0    free]
>>>   PV /dev/mapper/EMC_0105    is in exported VG vg_mds [16.84 GB / 0    free]
>>>   PV /dev/mapper/EMC_0103    is in exported VG vg_mds [16.84 GB / 0    free]
>>>   PV /dev/mapper/EMC_0101    is in exported VG vg_mds [16.84 GB / 0    free]
>>>   PV /dev/mapper/EMC_00FF    is in exported VG vg_mds [16.84 GB / 0    free]
>>>   PV /dev/mapper/EMC_00FD    is in exported VG vg_mds [16.84 GB / 0    free]
>>>   PV /dev/cciss/c0d0p4      VG vg00     lvm2 [129.58 GB / 44.00 MB free]
>>>   Total: 13 [331.71 GB] / in use: 13 [331.71 GB] / in no VG: 0 [0   ]
>>>
>>> *VGSCAN
>>> *# vgscan -vv
>>>       Setting global/locking_type to 1
>>>       File-based locking selected.
>>>       Setting global/locking_dir to /var/lock/lvm
>>>     Wiping cache of LVM-capable devices
>>>     Wiping internal VG cache
>>>   Reading all physical volumes.  This may take a while...
>>>     Finding all volume groups
>>>       /dev/cciss/c0d0: size is 286677120 sectors
>>>       /dev/cciss/c0d0p1: size is 208782 sectors
>>>       /dev/cciss/c0d0p1: size is 208782 sectors
>>>       /dev/cciss/c0d0p1: No label detected
>>>       /dev/cciss/c0d0p2: size is 4209030 sectors
>>>       /dev/cciss/c0d0p2: size is 4209030 sectors
>>>       /dev/cciss/c0d0p2: No label detected
>>>       /dev/cciss/c0d0p3: size is 10490445 sectors
>>>       /dev/cciss/c0d0p3: size is 10490445 sectors
>>>       /dev/cciss/c0d0p3: No label detected
>>>       /dev/cciss/c0d0p4: size is 271755540 sectors
>>>       /dev/cciss/c0d0p4: size is 271755540 sectors
>>>       /dev/cciss/c0d0p4: lvm2 label detected
>>>       /dev/mapper/EMC_0113: size is 35358720 sectors
>>>       /dev/mapper/EMC_0113: size is 35358720 sectors
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: size is 35358720 sectors
>>>       /dev/mapper/EMC_0111: size is 35358720 sectors
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: size is 35358720 sectors
>>>       /dev/mapper/EMC_010F: size is 35358720 sectors
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: size is 35358720 sectors
>>>       /dev/mapper/EMC_010D: size is 35358720 sectors
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: size is 35358720 sectors
>>>       /dev/mapper/EMC_010B: size is 35358720 sectors
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: size is 35358720 sectors
>>>       /dev/mapper/EMC_0109: size is 35358720 sectors
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: size is 35358720 sectors
>>>       /dev/mapper/EMC_0107: size is 35358720 sectors
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: size is 35358720 sectors
>>>       /dev/mapper/EMC_0105: size is 35358720 sectors
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: size is 35358720 sectors
>>>       /dev/mapper/EMC_0103: size is 35358720 sectors
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: size is 35358720 sectors
>>>       /dev/mapper/EMC_0101: size is 35358720 sectors
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: size is 35358720 sectors
>>>       /dev/mapper/EMC_00FF: size is 35358720 sectors
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: size is 35358720 sectors
>>>       /dev/mapper/EMC_00FD: size is 35358720 sectors
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0012: size is 9600 sectors
>>>       /dev/mapper/EMC_0012: size is 9600 sectors
>>>       /dev/mapper/EMC_0012: No label detected
>>>       Locking /var/lock/lvm/V_vg_mds RB
>>>     Finding volume group "vg_mds"
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>       /dev/mapper/EMC_0113: lvm2 label detected
>>>       /dev/mapper/EMC_0111: lvm2 label detected
>>>       /dev/mapper/EMC_010F: lvm2 label detected
>>>       /dev/mapper/EMC_010D: lvm2 label detected
>>>       /dev/mapper/EMC_010B: lvm2 label detected
>>>       /dev/mapper/EMC_0109: lvm2 label detected
>>>       /dev/mapper/EMC_0107: lvm2 label detected
>>>       /dev/mapper/EMC_0105: lvm2 label detected
>>>       /dev/mapper/EMC_0103: lvm2 label detected
>>>       /dev/mapper/EMC_0101: lvm2 label detected
>>>       /dev/mapper/EMC_00FF: lvm2 label detected
>>>       /dev/mapper/EMC_00FD: lvm2 label detected
>>>   Found exported volume group "vg_mds" using metadata type lvm2
>>>       Unlocking /var/lock/lvm/V_vg_mds
>>>       Locking /var/lock/lvm/V_vg00 RB
>>>     Finding volume group "vg00"
>>>       /dev/cciss/c0d0p4: lvm2 label detected
>>>       /dev/cciss/c0d0p4: lvm2 label detected
>>>   Found volume group "vg00" using metadata type lvm2
>>>       Unlocking /var/lock/lvm/V_vg00
>>>
>>> brem belguebli wrote:
>>>   
>>>     
>>>       
>>>> Hi,
>>>>
>>>> Never had no problem with it.
>>>>
>>>> The only problem I've hit was due to the binding file being, by
>>>> default, located in /var/lib/multipath, which is in my setup on a
>>>> separate LV than /, during boot time the devices were not correctly
>>>> created.
>>>>
>>>> Just had to switch the binding file to /etc and now no more problem.
>>>>
>>>> extract of my /etc/multipath.conf :
>>>>
>>>>
>>>> defaults {
>>>> ...
>>>>         flush_on_last_del       yes
>>>>         user_friendly_names     yes
>>>>         bindings_file "/etc/multipath_bindings"
>>>> }
>>>>
>>>> 2010/1/4 Bryn M. Reeves <bmr@redhat.com>:
>>>>   
>>>>     
>>>>       
>>>>         
>>>>> On Wed, 2009-12-30 at 12:52 +0100, brem belguebli wrote:
>>>>>     
>>>>>       
>>>>>         
>>>>>           
>>>>>> Hi,
>>>>>>
>>>>>> see man 5 lvm.conf there is an option called preferred_names which is
>>>>>> well explained
>>>>>>
>>>>>> It'll instruct lvm to use the preferred_names you configured in the
>>>>>> lvm.conf file if they exist
>>>>>>
>>>>>> ie : preferred_names = "/dev/mpath/" will use /dev/mpath/XXX instead
>>>>>> of /dev/mapper/XXX
>>>>>>       
>>>>>>         
>>>>>>           
>>>>>>             
>>>>> It's best not to use the symlinks in /dev/mpath - they are not always
>>>>> reliable. Use the device nodes created in /dev/mapper instead.
>>>>>
>>>>> Regards,
>>>>> Bryn.
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> linux-lvm mailing list
>>>>> linux-lvm@redhat.com
>>>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>>>
>>>>>     
>>>>>       
>>>>>         
>>>>>           
>>>> _______________________________________________
>>>> linux-lvm mailing list
>>>> linux-lvm@redhat.com
>>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>>   
>>>>     
>>>>       
>>>>         
>>>   
>>>     
>>>       
>>   
>>     
>
>   

-- 
Simon Loewenthal/Tele2
GSM: +31 6 2000 5427

******** IMPORTANT NOTICE ********
Please repect the X-Reply to klunky.co.uk. PGP available 0xD86A5A17. 
S/MIME PKCS12 key available for Lotus Notes: Please ask me for it.
This e-mail (including any attachments) may contain information that is confidential or otherwise protected from disclosure and it is intended only for the addressees. If you are not the intended recipient, please note that any copying, distribution or other use of information contained in this e-mail (and its attachments) is not allowed. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message (including any attachments) from your system.
Please note that e-mail messages may contain computer viruses or other defects, may not be accurately replicated on other systems, or may be subject of unauthorized interception or other interference without the knowledge of sender or recipient. Tele2 only send and receive e-mails on the basis that Tele2 is not responsible for any such computer viruses, corruption or other interference or any consequences thereof.  It ought to be obvious that my views do not represent my employer's views.

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2010-01-11 14:12               ` Simon Loewenthal/NL/Tele2
@ 2010-01-11 15:18                 ` Eugene Vilensky
  2010-01-11 16:06                   ` Simon Loewenthal/NL/Tele2
  0 siblings, 1 reply; 17+ messages in thread
From: Eugene Vilensky @ 2010-01-11 15:18 UTC (permalink / raw)
  To: simon.loewenthal, LVM general discussion and development

> How do I really know LVM is really using the mutlipath other than
> disabling one of the ports on the switch, which I don't wish to do on a
> production box.

man multipath, specifically the -l and -ll flags.

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2010-01-11 15:18                 ` Eugene Vilensky
@ 2010-01-11 16:06                   ` Simon Loewenthal/NL/Tele2
  2010-01-12  1:13                     ` Eugene Vilensky
  0 siblings, 1 reply; 17+ messages in thread
From: Simon Loewenthal/NL/Tele2 @ 2010-01-11 16:06 UTC (permalink / raw)
  To: LVM general discussion and development

I don't see the connection with multipath and the lvm.conf?  Multipath
is running well.
The setting :

write_cache_state = 1 

is in the lvm.conf.





Eugene Vilensky wrote:
>> How do I really know LVM is really using the mutlipath other than
>> disabling one of the ports on the switch, which I don't wish to do on a
>> production box.
>>     
>
> man multipath, specifically the -l and -ll flags.
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>   

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi
  2010-01-11 16:06                   ` Simon Loewenthal/NL/Tele2
@ 2010-01-12  1:13                     ` Eugene Vilensky
  0 siblings, 0 replies; 17+ messages in thread
From: Eugene Vilensky @ 2010-01-12  1:13 UTC (permalink / raw)
  To: LVM general discussion and development

On Mon, Jan 11, 2010 at 10:06 AM, Simon Loewenthal/NL/Tele2
<simon.loewenthal@klunky.co.uk> wrote:
> I don't see the connection with multipath and the lvm.conf? �Multipath
> is running well.

<quote>
How do I really know LVM is really using the mutlipath other than
disabling one of the ports on the switch, which I don't wish to do on a
production box.
</quote>

multipath -ll will show you your multipath topology.  you can then see
if the top-level multipath device matches the pvs that are in use
(such as pvdisplay -v).

For "testing" multipathing, which you say is running well, look into
dmsetup with which you can alter the topology and remove paths.

^ permalink raw reply	[flat|nested] 17+ messages in thread

end of thread, other threads:[~2010-01-12  1:14 UTC | newest]

Thread overview: 17+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-12-30 10:18 [linux-lvm] LVM preference for multipath verses disk/by-id/scsi Simon Loewenthal/NL/Tele2
2009-12-30 10:31 ` Simon Loewenthal/NL/Tele2
2009-12-30 11:52   ` brem belguebli
2009-12-30 12:37     ` Simon Loewenthal/NL/Tele2
2009-12-30 12:40       ` Simon Loewenthal/NL/Tele2
2009-12-30 13:00       ` brem belguebli
2009-12-30 13:45         ` Simon Loewenthal/NL/Tele2
2009-12-30 14:15           ` Simon Loewenthal/NL/Tele2
2010-01-04 12:54     ` Bryn M. Reeves
2010-01-04 13:17       ` brem belguebli
2010-01-05 10:52         ` Simon Loewenthal/NL/Tele2
2010-01-05 11:25           ` Simon Loewenthal/NL/Tele2
2010-01-05 16:12             ` Simon Loewenthal/NL/Tele2
2010-01-11 14:12               ` Simon Loewenthal/NL/Tele2
2010-01-11 15:18                 ` Eugene Vilensky
2010-01-11 16:06                   ` Simon Loewenthal/NL/Tele2
2010-01-12  1:13                     ` Eugene Vilensky

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).