[Sheepdog] [PATCH v4 11/12] sheep: add cluster snapshot/restore support

[Liu Yuan]

On 12/30/2011 02:50 PM, tao.peng at emc.com wrote:

> How does the above become a cluster wide snapshot? From what I read, farm.snapshot only ensures single node's dirty objects to be snapshotted. Or am I missing something?
> 


Yes, snapshot operation of the Farm backend store is on node basis. We
just send an cluster-wide message that request for snapshot operations
on each node.

Currently, Farm doesn't support *live* snapshot, so it safe for us to do
a cluster-wide snapshot without on-the-fly IO requests. And those
snapshot objects are distributed on each backend store.

Thanks,
Yuan