I found this email buried in my inbox.
1) I suspect the reason why your MDS backup took so long is because you
are not using the "--sparse" option for tar, or are otherwise using an old
version of tar that does not automatically make sparse backups. That was
in the RHEL6 version of tar, and eventually pushed upstream (1.29 bubbles
up in my memory) but I'm not sure about the SLES version.
2) probably not an issue
3) Lustre doesn't store xattrs on symlinks
Cheers, Andreas
On 2014/06/27, 2:59 AM, "Ramiro Alba" <raq(a)cttc.upc.edu> wrote:
Hello everybody,
I am currently using Lustre 1.8.5 at servers, with a SLES kernel
(2.6.32.19-0.2.1-lustre.1.8.5).
Before this year is over, I'll upgrade to the current Lustre Maintenance
release
(currently 2.4.X), but now I need to arrange a MDT moving, to other LUN
in the MDS.
I did a test on a MDT LVM snapshot, following the moving procedure
described bellow, but I
found some issues I would like to comment:
1) The backup using the tar command took very long time (20 hours),
though the
MDT is quite small (197 MB). So long?
2) The restored 'ldiskfs' file system is a bit smaller than the original
one (about 20 MB
using du -sm). Should I worry?
3) When backing up Extended attributes with the command 'getfattr' I get
some errors of
the type:
getfattr: ./ROOT/<file path>: No such file or directory
I could see that they are symbolic links using absolute paths. Can
that be a problem?
Finally, I got the bellow procedure from the 1.8.X Lustre manual. Any
comment?
**************************************************************
MDT MOVING PROCEDURE
**************************************************************
----------------------------------------------------------
- Backup procedure
----------------------------------------------------------
1) Mount lustre as 'ldiskfs' type
mount -t ldiskfs /dev/sdb /lustre/mds
2) Change to the file system mount point
cd /lustre/mds
3) Backup all the file system data
tar cSf /backup/mds.tar .
4) Backup Extended Attributes
getfattr -R -d -m '.*' -P . > /backup/ea.bak
5) Umount the file system
cd
umount /lustre/mds
----------------------------------------------------------
- Restore procedure
----------------------------------------------------------
1) Make a receiving lustre MDT
mkfs.lustre --fsname=jffstg --param mdt.quota_type=ug \
--reformat --mdt --mgs /dev/sdc
2) Mount lustre as 'ldiskfs' type
mount -t ldiskfs /dev/sdc /lustre/mds
3) Change to the file system mount point
cd /lustre/mds
4) Restore the previous tar file
tar xpSf /backup/mds.tar
5) Restore de file system Extended Attributes
setfattr --restore=/backup/ea.bak
6) Remove the recovery logs
rm OBJECTS/* CATALOGS
--
Ramiro Alba
Centre Tecnològic de Tranferència de Calor
http://www.cttc.upc.edu
Escola Tècnica Superior d'Enginyeries
Industrial i Aeronàutica de Terrassa
Colom 11, E-08222, Terrassa, Barcelona, Spain
Tel: (+34) 93 739 8928
--
Aquest missatge ha estat analitzat per MailScanner
a la cerca de virus i d'altres continguts perillosos,
i es considera que est� net.
Cheers, Andreas
--
Andreas Dilger
Lustre Software Architect
Intel High Performance Data Division