[Lustre-discuss] lfs find

[Dilger, Andreas]

On 2014/11/06, 6:51 AM, "Jon Tegner" <tegner at foi.se> wrote:
>Short question (using lustre 2.5.3). Have added a new OST and about to
>remove a faulty one. After deactivating it I would like to migrate the
>data from the faulty one, in chapter 14  the command:
>
>lfs find --obd  ost_name /mount/point | lfs_migrate -y
>
>is given, and in chapter 19:
>
>lfs find --ost {OST_UUID} lfs_migrate -y
>
>Are these two command equivalent?

Yes, they are aliases for the same operation.  The "ost_name" or
"ost_uuid" is of the form {fsname}-OSTnnnn, like "testfs-OST0003" or
similar (the trailing "_UUID" isn't required).  The number is in hex, as
listed by "lfs df" or "lfs osts"s.

>And just to be certain, once the migration is finish should the command:
>
>lctl conf_param ost_name.osc.active=0
>
>be run on all clients as well as on the MDS?

No, just on the MGS.  This will permanently disable the OST on the MDS and
all clients.

> And how to I find the name "ost_name.osc" in the command above
>(llobdstat states it can be found under /proc/fs/lustre/obdfilter - but
>no such file on my system)?

See above.

Cheers, Andreas
-- 
Andreas Dilger

Lustre Software Architect
Intel High Performance Data Division