Re: XFS disaster recovery

Dave Chinner
2022-02-02T02:48:06Z

On Tue, Feb 01, 2022 at 08:20:45PM -0500, Sean Caron wrote:
> Thank you for the detailed response, Dave! I downloaded and built the
> latest xfsprogs (5.14.2) and tried to run a metadump with the
> parameters:
>
> xfs_metadump -g -o -w /dev/md4 /exports/home/work/md4.metadump
>
> It says:
>
> Metadata CRC error detected at 0x56384b41796e, xfs_agf block 0x4d7fffd948/0x1000
> xfs_metadump: cannot init perag data (74). Continuing anyway.
>
> It starts counting up inodes and gets to "Copied 418624 of 83032768
> inodes (1 of 350 AGs)"
>
> The it stops with an error:
>
> xfs_metadump: inode 2216156864 has unexpected extents

Not promising - that's a device inode (blk, chr, fifo or sock) that
appears to have extents in the data fork. That's indicative of the
inode cluster containing garbage, but unfortunately the error
propagation from a bad inode appears to abort the rest of the
metadump.

That looks like a bug in metadump to me.

Let me confirm this and work out how it should behave and I'll
send you a patch to avoid this issue.

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com