[Lustre-discuss] Lustre-discuss Digest, Vol 45, Issue 6

[Andreas Dilger]

On Oct 06, 2009  20:24 -0700, Dam Thanh Tung wrote:
> > RAID5 over RAID1? Nahh. Consider http://WWW.BAARF.com/ and that
> > the storage system of a Lustre pool over DRBD is ideally suited to
> > RAID10 (with each pair a DRBD resource). RAID5 may be contributing
> > to your speed problem below because of or being rebuilt/syncing
> > itself.
>
> Poor me, i don't know it before, so now we can't change anything on my
> raid partition :( .

It is documented in the Lustre manual that the MDS should be running
on RAID-1 or RAID-1+0.

I would suggest to shut down your MDS, make sure your remote DRBD copy
is up-to-date, then reformat the local storage into RAID-1+0, copy
the remote DRBD mirror back to the local system, and then reformat
the remote DRBD storage to RAID-1+0 also and copy it there.

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