[Lustre-discuss] how to reuse OST indices (EADDRINUSE)

[Craig Prescott]

Hello list,

We recently evacuated several OSTs on a single OSS, replaced RAID 
controllers, re-initialized RAIDs for new OSTs, and made new lustre 
filesystems for them, using the same OST indices as we had before.

The filesystem and all its clients have been up and running the whole 
time.  We disabled the OSTs we were working on on all clients and our 
MGS/MDS (lctl dl shows them as "IN" everywhere).

Now we want to bring the newly-formatted OSTs back online.  When we try 
to mount the "new" OSTs, we get this for each one in this syslog of the 
OSS that has been under maintenance:

> Lustre: MGC10.13.28.210 at o2ib: Reactivating import
> LustreError: 11-0: an error occurred while communicating with 10.13.28.210 at o2ib. The mgs_target_reg operation failed with -98
> LustreError: 6065:0:(obd_mount.c:1097:server_start_targets()) Required registration failed for cms-OST0006: -98
> LustreError: 6065:0:(obd_mount.c:1655:server_fill_super()) Unable to start targets: -98
> LustreError: 6065:0:(obd_mount.c:1438:server_put_super()) no obd cms-OST0006
> LustreError: 6065:0:(obd_mount.c:147:server_deregister_mount()) cms-OST0006 not registered

What do we need to do to get these OSTs back into the filesystem?

We really want to reuse the original indices.

This is Lustre 1.8.4, btw.

Thanks,
Craig Prescott
UF HPC Center