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

[Michael D. Seymour]

Peter Jones wrote:
> A bug has been identified in 1.6.7 that can cause directory corruptions 
> on the MDT. A patch and full details are in bug 18695 - 
> https://bugzilla.lustre.org/show_bug.cgi?id=18695
> 
> We recommend to anyone running 1.6.7 on the MDS to unmount the MDT, run 
> e2fsck against the MDT device and apply the patch from bug 18695 as soon 
> as possible.
> 
> Please note that the landing that caused the regression was that for 
> 11063, so anyone running with that patch on an earlier 1.6.x release 
> should also follow the above procedure.
> 
> This fix will be included in 1.8.0 and we will also create an ad hoc 
> 1.6.7.1 release to provide this fix as soon as possible. 1.6.7 will be 
> withdrawn from the Sun Download Center
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> Lustre-discuss at lists.lustre.org
> http://lists.lustre.org/mailman/listinfo/lustre-discuss

Hi Peter, all,

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?

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.

Thanks for any help,
Mike S.

-- 
Michael D. Seymour                 Phone: 416-978-1776
Scientific Computing Support       Fax: 416-978-3921
Canadian Institute for Theoretical Astrophysics, University of Toronto