Re: xfs_repair of critical volume

Eric Sandeen
2010-11-01T22:20:08Z

On 10/31/10 2:54 AM, Eli Morris wrote:
> I have a large XFS filesystem (60 TB) that is composed of 5 hardware
> RAID 6 volumes. One of those volumes had several drives fail in a
> very short time and we lost that volume. However, four of the volumes
> seem OK. We are in a worse state because our backup unit failed a
> week later when four drives simultaneously went offline. So we are in
> a bad very state. I am able to mount the filesystem that consists of
> the four remaining volumes. I was thinking about running xfs_repair
> on the filesystem in hopes it would recover all the files that were
> not on the bad volume, which are obviously gone. Since our backup is
> gone, I'm very concerned about doing anything to lose the data that
> will still have. I ran xfs_repair with the -n flag and I have a
> lengthly file of things that program would do to our filesystem. I
> don't have the expertise to decipher the output and figure out if
> xfs_repair would fix the filesystem in a way that would retain our
> remaining data or if it would, let's say t!

One thing you could do is make an xfs_metadump image, xfs_mdrestore
it to a sparse file, and then do a real xfs_repair run on that.
You can then mount the repaired image and see what's there.
So from a metadata perspective, you can do a real-live repair
run on an image, and see what happens.

-Eric