Re: bad superblock after lvextend

["Frank J. Buchholz" <frankb@xxxxxxxxx>]

I was able to activate the filesystem using lvm however now when I run 
xfs_repair on the file system it complains about the superblock not 
being found and then continues to generate the following errors about 
secondary superblocks.
# xfs_repair -o assume_xfs -v /dev/mapper/Volume00-LogVol00
Phase 1 - find and verify superblock...
error reading superblock 31 -- seek to offset 2129889329152 failed
couldn't verify primary superblock - bad magic number !!!

attempting to find secondary superblock...
...........................................

....found candidate secondary superblock...
error reading superblock 31 -- seek to offset 2129889329152 failed
unable to verify superblock, continuing...

This message repeats every hour or so on a 2TB filesystem.

Is there anything I can do with xfs_db to help resolve this problem?

Thanks,
Frank

Frank J. Buchholz wrote:

> ------------------------------------------------------------------------
>
> Subject:
> bad superblock after lvextend
> From:
> "Frank J. Buchholz" <frankb@xxxxxxxxx>
> Date:
> Mon, 22 Nov 2004 19:25:32 -0500
> To:
> linux-xfs@xxxxxxxxxxx
>
> To:
> linux-xfs@xxxxxxxxxxx
>
>
> Hello,
>
> I recently attempted to extend my logical volume. First I added an 
> additional physical volume to an existing volume group. This worked fine.
> vgextend Volume00 /dev/sba
>
> However when it came time to run the lvextend command I received a 
> number of device-mapper errors.
> lvm> lvextend -L+1G /dev/Volume00/LogVol00
>  Extending logical volume LogVol00 to 2.93 TB
>  device-mapper ioctl cmd 9 failed: Invalid argument
>  Couldn't load device 'Volume00-LogVol00'.
>  Problem reactivating LogVol00
>
> While I was trying to determine what the errors were I noticed that 
> the filesystem that sits on the logical volume being extended was no 
> longer available. I attempted to umount the filesystem however the 
> command froze. I then rebooted the system without mounting the 
> filesystem in question and manually mounted the filesystem. XFS 
> reported back that it could not locate the superblock.
> I then ran xfs_repair...
> # xfs_repair /dev/Volume00/LogVol00
> Phase 1 - find and verify superblock...
> superblock read failed, offset 0, size 524288, ag 0, rval 0
>
> fatal error -- Invalid argument
>
> Is it possible to repair this problem either through LVM or XFS? I 
> noticed there are a number of achieved .vg files in /etc/lvm/archive, 
> is it possible to restore LVM from one of these? Or is it possible to 
> rebuild the superblock?
> Thanks,
> Frank