[Lustre-discuss] Delete ost

[Kevin Van Maren]

Wang Yibin wrote:
> Hello,
>
> 在 2010-11-19，上午3:21， Thomas Johansson 写道：
>
>>> I am not sure I understand - Do you have multiple filesystems
>>> sharing the
>>> same MGS?
>>
>> Yes 5 filesystems on 4 OSS:s and 2 MDS in active/passive failover.
>> Some 100 TB of space in total.
>
> Probably you misunderstood me. You seems to be using 1
> filesystem(MDSx2/OSSx4) with 5 clients.
> Making 5 lustre filesystems out of 4OSS/2MDS is a mission-impossible.

No, while it is not often done, there is nothing to prevent 5 Lustre
file systems from running on 4 OSS nodes and 2 MDS nodes.
In addition to the MGS, each file system needs one MDT and 1 or more
OSTs. An OSS can serve up OSTs for multiple file systems, and an MDS
node can serve up MDTs for multiple file systems (and a node could even
be both an MDS and OSS at the same time).

Now, if there were a separate MGS for each file system, then it would be
a different story... each node can really only serve up OSTs or MDTs for
a single MGS.

Kevin