[Lustre-discuss] What says an OST is deactivated?

[Andreas Dilger]

On Mar 25, 2008  01:28 -0600, Chris Worley wrote:
> I do an "lctl dl" and it shows "UP" in the first column for all
> OST's... even though I've deactivated many disks.  "iostat" shows the
> disks are still in use too.

What does it mean when you say "deactivated many disks"?

> I'm trying to get rid of slow disks... what's the right way to tell
> Lustre to quit using a disk?

If you deactivate an OST on the MDS node it will stop allocating new
files there, and if your files are deleted by some process (e.g. aging
or jobs running) the inactive OSTs will eventually become empty.  If
you want to speed this up you should use "lfs find -o {OST}" to find
files on that OST and copy them to a new file.

If you deactivate OSTs on the client nodes and stop the OSTs then the
clients will return IO errors for any files remaining on those disks.
I doubt that is what you want.

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