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

[tao.peng at emc.com]

> -----Original Message-----
> From: Liu Yuan [mailto:namei.unix at gmail.com]
> Sent: Friday, December 30, 2011 3:06 PM
> To: Peng, Tao
> Cc: morita.kazutaka at lab.ntt.co.jp; sheepdog at lists.wpkg.org
> Subject: Re: [Sheepdog] [PATCH v4 11/12] sheep: add cluster snapshot/restore support
> 
> 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.
> 
I see. Thanks for the explanation.

Cheers,
Tao