On Apr 04, 2009 00:32 -0500, dan wrote:> I was switching MDS servers, all new hardware. I followed the backup and
> restore procedures in the manual and some tips from the list. When it was
> all said and done the OSTs mounted up and I could mount a client just fine.
> It seemed like everything was fine until I realized all the files on the
> system are zero length instead of 100''s of GB. What happened?
It sounds like you did not back up the extended attributes. IIRC is a
step in the restore process that verifies that the attributes were
restored correctly.
> Background:
>
> I used rsync -aXvv. It was very very slow over ssh or native rsync so I
> mounted the old MDS partition via NFS on the new server - I think this
> might be the problem. Do the extended attributes transfer over NFS?
I don''t think there is support for this in NFS.
> Some files in /ROOT ended up being 80 MB instead of the normal 512 byte MDT
> files. The original file system was 794 MB, the new one is 166 GB.
>
> I can create new files that are normal. Performance is good.
I would NOT continue creating new files until you have successfully
restored all of the attributes. You can re-copy the xattrs by themselves
by mounting the old MDS with -t ldiskfs and using "getfattr" as
documented,
and then "setfattr" on the new MDS.
> I''m currently running e2fsck to build the databases for lfsck.
Will that
> help or hurt this problem? What''s the best way to recover from
this?
> Thank you!
This will not help you, and would likely erase all of your data objects
if you run lfsck with that database.
Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.