[linux-lvm] Broken hard disk

[linux-lvm] Broken hard disk

[Martin Wilmes]

Hi,

I had a standard Fedora Core 4 installation with the root fs and swap 
on LVM. I upgraded to Core 5. Everything worked fine. No need to be an LVM 
guru so far.

Then I added a new hard disk to the computer and a partition of this new disk 
to the root volume. The "new" hard disk then broke down so that I am unable 
to access the data on the root volume.

Now I installed the old, hopefully still working disk in a different computer 
and booted with Knoppix 5.0.1 to get some of my data back but vgscan -v comes 
back with nothing at all.

fdisk says

Disk /dev/hda: 20.5 GB, 20525137920 bytes
255 heads, 63 sectors/track, 2495 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hda1   *           1          13      104391   83  Linux
/dev/hda2              14        2495    19936665   8e  Linux LVM

Any suggestions how to recover that volume?

Thanks
Martin

Re: [linux-lvm] Broken hard disk

[Bryn M. Reeves]

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Martin Wilmes wrote:
> Now I installed the old, hopefully still working disk in a different computer 
> and booted with Knoppix 5.0.1 to get some of my data back but vgscan -v comes 
> back with nothing at all.

It's a bit strange that it outputs nothing at all. I'd expect to see
something like:

$ sudo vgscan -v
    Wiping cache of LVM-capable devices
    Wiping internal VG cache
  Reading all physical volumes.  This may take a while...
    Finding all volume groups
    Finding volume group "scratch0"
  Couldn't find device with uuid 'ZpQI30-qpx3-Cm54-YcSR-5Ho4-rlUx-uCxGBi'.
  Couldn't find all physical volumes for volume group scratch0.
  Couldn't find device with uuid 'ZpQI30-qpx3-Cm54-YcSR-5Ho4-rlUx-uCxGBi'.
  Couldn't find all physical volumes for volume group scratch0.
  Volume group "scratch0" not found

If there's a PV missing from the volume group.

You can add move 'v's to increase the verbosity of vgscan to see what
it's scanning - do you have any device filters configured in /etc/lvm.conf?

It'd also be good to see what pvscan shows, for e.g.:

$ sudo pvscan
  Couldn't find device with uuid 'ZpQI30-qpx3-Cm54-YcSR-5Ho4-rlUx-uCxGBi'.
  PV /dev/hda2        VG d800_vg0   lvm2 [34.18 GB / 760.00 MB free]
  PV unknown device   VG scratch0   lvm2 [60.00 MB / 0    free]
  PV /dev/loop1       VG scratch0   lvm2 [60.00 MB / 52.00 MB free]
  Total: 3 [34.30 GB] / in use: 3 [34.30 GB] / in no VG: 0 [0   ]

Once you find the volume group, activate it without the missing PV using
the --patial option, e.g:

vgchange -ay --partial <vgname>


Cheers,

Bryn.
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Re: [linux-lvm] Broken hard disk

[Martin Wilmes]

On Friday, 13. October 2006 00:53, Bryn M. Reeves wrote:
> You can add move 'v's to increase the verbosity of vgscan to see what
> it's scanning - do you have any device filters configured in /etc/lvm.conf?

No filters, everything is commented out (unchanged).

vgscan -vvv now generates ouput for hda:

...
      /dev/hda1: size is 208782 sectors
        Closed /dev/hda1
      /dev/hda1: size is 208782 sectors
        Opened /dev/hda1 RO O_DIRECT
        /dev/hda1: block size is 1024 bytes
        Closed /dev/hda1
        Using /dev/hda1
        Opened /dev/hda1 RO O_DIRECT
        /dev/hda1: block size is 1024 bytes
      /dev/hda1: No label detected
        Closed /dev/hda1
        /dev/loop1: Skipping (sysfs)
        /dev/cloop1: Skipping: Unrecognised LVM device type 240
...

> It'd also be good to see what pvscan shows, for e.g.:

pvscan -vvv outputs:

...
      /dev/hda1: size is 208782 sectors
        Closed /dev/hda1
      /dev/hda1: size is 208782 sectors
        Opened /dev/hda1 RO O_DIRECT
        /dev/hda1: block size is 1024 bytes
        Closed /dev/hda1
        Using /dev/hda1
        Opened /dev/hda1 RO O_DIRECT
        /dev/hda1: block size is 1024 bytes
      /dev/hda1: No label detected
        Closed /dev/hda1
        /dev/loop1: Skipping (sysfs)
        /dev/cloop1: Skipping: Unrecognised LVM device type 240
...

Thanks
Martin

Re: [linux-lvm] Broken hard disk

[Bryn M. Reeves]

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Martin Wilmes wrote:
> On Friday, 13. October 2006 00:53, Bryn M. Reeves wrote:
>> You can add move 'v's to increase the verbosity of vgscan to see what
>> it's scanning - do you have any device filters configured in /etc/lvm.conf?
> 
> No filters, everything is commented out (unchanged).
> 
> vgscan -vvv now generates ouput for hda:
> 
> ...
>       /dev/hda1: size is 208782 sectors
>         Closed /dev/hda1
>       /dev/hda1: size is 208782 sectors
>         Opened /dev/hda1 RO O_DIRECT
>         /dev/hda1: block size is 1024 bytes
>         Closed /dev/hda1
>         Using /dev/hda1
>         Opened /dev/hda1 RO O_DIRECT
>         /dev/hda1: block size is 1024 bytes
>       /dev/hda1: No label detected
>         Closed /dev/hda1
>         /dev/loop1: Skipping (sysfs)
>         /dev/cloop1: Skipping: Unrecognised LVM device type 240
> ...

What about hda2? According to your fdisk output, that's the PV on this disk.

Does hda2 appear in /proc/partitions?

>> It'd also be good to see what pvscan shows, for e.g.:
> 
> pvscan -vvv outputs:
> 

Likewise - all I can see here is hda1 - that's a type 0x83 (Linux)
partition, rather than the 0x8e (Linux LVM) partition that we're
interested in here.

Can you put the complete output of vgscan -vvv and pvscan -vvv somewhere
on the web and post the links here?

You can use a pastedump service like http://p.opsat.net/new if you don't
have access to somewhere to host this.

Cheers,

Bryn.

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Re: [linux-lvm] Broken hard disk

[Martin Wilmes]

On Friday, 13. October 2006 18:33, Bryn M. Reeves wrote:
> Martin Wilmes wrote:
> > On Friday, 13. October 2006 00:53, Bryn M. Reeves wrote:

> > ...

> >         Closed /dev/hda1
> >         /dev/loop1: Skipping (sysfs)
> >         /dev/cloop1: Skipping: Unrecognised LVM device type 240
> > ...
>
> What about hda2? According to your fdisk output, that's the PV on this
> disk.

Sorry, that was really silly.

> Does hda2 appear in /proc/partitions?

Yes, it does.

> >> It'd also be good to see what pvscan shows, for e.g.:
> >
> > pvscan -vvv outputs:
>
> Likewise - all I can see here is hda1 - that's a type 0x83 (Linux)
> partition, rather than the 0x8e (Linux LVM) partition that we're
> interested in here.
>
> Can you put the complete output of vgscan -vvv and pvscan -vvv somewhere
> on the web and post the links here?

Here are the links:

http://java-cup.de/~wilmes/lvm/pvscan.txt
http://java-cup.de/~wilmes/lvm/vgscan.txt

Thanks again for your patience.
Martin