[Lustre-discuss] Moving storage from one OSS to another

[Ashley Pittman]

On 8 Aug 2011, at 04:57, Rafa Griman wrote:
> I know we could "just add" and restripe the existing files. But the
> customer wants to physically move 100 drives from the existing S2A9900
> to the new one in order to have 400 drives on one S2A9900 and 400
> drives on the other one.

It would be more balanced if they do that.

> So my questions are:
>     1.- Can this be done (move drives between OSTs) without losing data?

Moving drives between OSTs does not make sense - the OST is the data stored on the drives.  It is possible to move drives between controllers, you should contact DDN support for advice on this.

>     2.- Can an OST be moved from one OSS to another without losing data?

Yes, you need to use tunefs.lustre for this.

>     3.- Has anyone done this? How?

We've done this, not frequently or as part of standard maintenance but it's not unusual when expanding filesystems in the way you are.

Ashley.