[Lustre-discuss] WARNING: Potential directory corruptions on the MDS with 1.6.7

[Andreas Dilger]

On Apr 09, 2009  17:11 -0400, Michael D. Seymour wrote:
> Is there an accepted procedure for recovering from any introduced errors from 
> this bug? i.e. performing e2fsck with the --mdsdb option on the MDT, lfsck on 
> the OSTs? Or simply do an e2fsck on the unmounted MDT, downgrade and remount?

No, there is no lustre-specific mechanism for recovery for this
problem.  This may result in files being put into the underlying
lost+found directory, which you might consider moving into a
newly-created ROOT/lost+found directory by mounting the MDS as
"-t ldiskfs".  You shouldn't just move the filesystem lost+found
directory, as that can cause trouble at a later time.

> I performed the following on one of our 17 TB lustre fs, containing disposable 
> data. I performed the following:
> 
> umount mdt
> e2fsck /dev/md2 # mdt device
> Say yes to all repair queries
> downgrade to 1.6.6
> mount mdt
> 
> this resulted in <100 files out of 587k that had ? ? ? directory entries, but 
> everything else seems fine. I have not performed any checks of file consistency.
> 
> We have a second lustre file system that stores permanent data but I don't want 
> to rick any lost or corrupt files.
>

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.