From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx06.extmail.prod.ext.phx2.redhat.com [10.5.110.10]) by int-mx04.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id nBUBrB70031855 for ; Wed, 30 Dec 2009 06:53:11 -0500 Received: from fg-out-1718.google.com (fg-out-1718.google.com [72.14.220.158]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id nBUBqxpm030747 for ; Wed, 30 Dec 2009 06:53:00 -0500 Received: by fg-out-1718.google.com with SMTP id 19so513476fgg.9 for ; Wed, 30 Dec 2009 03:52:59 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <4B3B2C05.1070902@tele2.com> References: <4B3B28E5.5030208@tele2.com> <4B3B2C05.1070902@tele2.com> Date: Wed, 30 Dec 2009 12:52:58 +0100 Message-ID: <29ae894c0912300352k29bbd06dha89b7dd0045c550@mail.gmail.com> From: brem belguebli Content-Transfer-Encoding: 8bit Subject: Re: [linux-lvm] LVM preference for multipath verses disk/by-id/scsi Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="utf-8" To: simon.loewenthal@klunky.co.uk, 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 : > 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. 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