Re: [linux-lvm] vgchange partial mount fails

[Heinz Mauelshagen <mauelshagen@redhat.com>]

Hrm,

the mapping of the first segment to /dev/cdrom looks very bogus.
That would eyplain why there's no superblock to be found.

DO you have a metadata archive reflecting a correct mapping ?

Heinz

On Tue, Nov 08, 2005 at 11:06:09AM +0000, Tom Robinson wrote:
> Heinz Mauelshagen wrote:
> 
> >On Mon, Nov 07, 2005 at 10:12:32PM +0000, Tom Robinson wrote:
> > 
> >
> >>Hi,
> >>
> >>I'm trying to do a partial mount of a VG in order to rescue data from it
> >>(the last of the 8 PVs has died)
> >>
> >>If I do vgchange -P -a y vg1
> >>It says:
> >>
> >>Partial mode. Incomplete volume groups will be activated read-only.
> >>7 PV(s) found for VG vg1: expected 8
> >>Logical volume (lv1) contains an incomplete mapping table.
> >>7 PV(s) found for VG vg1: expected 8
> >>Logical volume (lv1) contains an incomplete mapping table.
> >>1 logical volume(s) in volume group "vg1" now active
> >>
> >>Which looks like it might have worked, but in /dev/mapper I have:
> >>
> >>crw-rw----  1 root root  10, 63 May 30 02:48 control
> >>brw-------  1 root root 254,  0 Oct 25 13:20 vg1-lv1
> >>
> >>But I can't mount vg1-lv1 (its ext2 - but it says "must specify fs type).
> >>   
> >>
> >
> >Looks like expected behaviour.
> >
> >You're likely missing the beginning of your filesystem which was mapped
> >to the dead PV and the fs code fails to find its metadata
> >(ie. superblock).
> >
> >Check with "lvdisplay -m /dev/vg1/lv1"
> > 
> >
> 
> Thanks for your response, Heinz,
> 
> vaus root # lvdisplay -m /dev/vg1/lv1
>  7 PV(s) found for VG vg1: expected 8
>  7 PV(s) found for VG vg1: expected 8
>  Volume group "vg1" not found
> 
> Thing is, /dev/vg1/lv1 doesn't exist at all,
> It used to, when everything was working.
> Only /dev/mapper exists.
> 
> I have had the server running for about 3 years,
> and only added the last (dead) PV about 2 months ago
> so would it still put the superblock there?
> 
> Any suggestions at all on how to rescue any data?
> 
> Oh, heres the first bit of output of lvdisplay -mP /dev/vg1/lv1
> if it helps:
> 
>  Partial mode. Incomplete volume groups will be activated read-only.
>  --- Logical volume ---
>  LV Name                /dev/vg1/lv1
>  VG Name                vg1
>  LV UUID                000000-0000-0000-0000-0000-0000-000000
>  LV Write Access        read/write
>  LV Status              available
>  # open                 1
>  LV Size                1.51 TB
>  Current LE             49447
>  Segments               7486
>  Allocation             normal
>  Read ahead sectors     1024
>  Block device           254:0
>  
>  --- Segments ---
>  Logical extent 0 to 4883:
>    Type                linear
>    Physical volume     /dev/cdrom
>    Physical extents    0 to 4883
>  
>  Logical extent 4884 to 8545:
>    Type                linear
>    Physical volume     /dev/hdf
>    Physical extents    0 to 3661
>  
>  Logical extent 8546 to 12051:
>    Type                linear
>    Physical volume     /dev/hde4
>    Physical extents    0 to 3505
>  
>  Logical extent 12052 to 19530:
>    Type                linear
>    Physical volume     /dev/hdh
>    Physical extents    0 to 7478
>  
>  Logical extent 19531 to 27009:
>    Type                linear
>    Physical volume     /dev/hda
>    Physical extents    0 to 7478
>  
>  Logical extent 27010 to 34488:
>    Type                linear
>    Physical volume     /dev/hdb
>    Physical extents    0 to 7478
>  
>  Logical extent 34489 to 41967:
>    Type                linear
>    Physical volume     /dev/hdc
>    Physical extents    0 to 7478
>  
>  Logical extent 41968 to 41968:
>    Type                linear
>    Physical volume     Missing
>  
>  Logical extent 41969 to 41969:
>    Type                linear
>    Physical volume     Missing
> 
> etc......
> 
> 
> Regards,
>  Tom
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> >Regards,
> >Heinz    -- The LVM Guy --
> >
> > 
> >
> vaus root # lvdisplay -m /dev/vg1/lv1
>  7 PV(s) found for VG vg1: expected 8
>  7 PV(s) found for VG vg1: expected 8
>  Volume group "vg1" not found
> 
> 
> 
> 
> >>What is wrong? Have I misconfigured lvm / dm?
> >>are there any lines I need in my config file?
> >>Are there any tools I can run to get more info?
> >>
> >>The array was built with LVM1 & 2.4.18,
> >>I'm now using LVM2/DM under 2.6.11.10
> >>
> >>Also, It looks like it has done something, because if I try
> >>to deactivate it with "vgchange -P -a n vg1" I get:
> >>
> >>Partial mode. Incomplete volume groups will be activated read-only.
> >>7 PV(s) found for VG vg1: expected 8
> >>Logical volume (lv1) contains an incomplete mapping table.
> >>Can't deactivate volume group "vg1" with 1 open logical volume(s)
> >>
> >>Any help greatly appreciated.
> >>Kind regards,
> >>Tom
> >>
> >>
> >>_______________________________________________
> >>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/
> >
> >
> > 
> >
> 
> _______________________________________________
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Heinz Mauelshagen                                 Red Hat GmbH
Consulting Development Engineer                   Am Sonnenhang 11
Cluster and Storage Development                   56242 Marienrachdorf
                                                  Germany
Mauelshagen@RedHat.com                            +49 2626 141200
                                                       FAX 924446
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