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

[Michael D. Seymour]

Andreas Dilger wrote:
> 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.
> 

So this would be the course of action.

 > umount /lustre/mdt
 > e2fsck /dev/md2 # mdt device
 > # Say yes to all repair queries
# Here then one would:
mkdir /root/MDT-lost+found
mount -t ldiskfs /dev/md2 /mnt/tmp
rsync -a /mnt/tmp/lost+found/ /root/MDT-lost+found
 > downgrade to 1.6.6
 > mount -t lustre /dev/md2 /lustre/mdt

I am unclear what use the left over files placed in lost+found from the 
MDT fs could be.

Thanks Andreas for your help,
Mike