[Lustre-discuss] Permanently removing an OST

[Andreas Dilger]

On 2010-05-26, at 16:49, Florent Parent wrote:
> A while ago, we experienced multi disk failures on a raid6 ost. We
> managed to migrate some data off the OST (lfs_migrate), and the
> process was long (software raid was often failing).
> 
> We reconstructed the target from scratch, which introduced a new OST.
> Following the Lustre documentation on "Removing an OST from the File
> System", we used the following procedure to permanently remove the old
> OST:
> 
> on MGS:
> lctl conf_param osc.lustre1-OST002f-osc.active.osc.active=0

If you specified the above, it is possible that you only deactivated it on the MDS, not on the clients as well.

> Many days later, and even following a complete server/clients reboot,
> we are now seeing this target being active on clients:
> 
> on MDT:
> [root at mds2 ~]# lctl get_param osc.lustre1-OST002f-osc.active
> osc.lustre1-OST002f-osc.active=0
> [root at mds2 ~]# lctl dl|grep 002f
> 51 UP osc lustre1-OST002f-osc lustre1-mdtlov_UUID 5

The device is configured, but if it is not active it will not be used for anything.

> on client:
> # ssh r101-n33 lctl dl |grep 002f
> 50 UP osc lustre1-OST002f-osc-ffff810377354000
> ef3f455a-7f67-134e-cf38-bcc0d9b89f26 4

What does "active" report for this OSC on a client?

Cheers, Andreas
--
Andreas Dilger
Lustre Technical Lead
Oracle Corporation Canada Inc.