[Lustre-discuss] Permanently removing an OST

[Florent Parent]

Hi,

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

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

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

What are we missing from the procedure here? I'm really looking at
*permanently* disabling OST from Lustre.

Thanks for any pointers.
Florent