[sheepdog] [PATCH] dog/farm: multi-thread cluster snapshot, save process

[Ruoyu]

On 2014年08月08日 19:45, Liu Yuan wrote:
> On Fri, Aug 08, 2014 at 05:11:55PM +0800, Liu Yuan wrote:
>> On Fri, Aug 08, 2014 at 05:02:48PM +0800, Ruoyu wrote:
>>> Will the operation affect VM?
>>> If yes, it would be better to let user choose it.
>> I guess yes. probably 'save --hard' will try this multi-thread.
>>
>> Thanks
>> Yuan
> For a second thought, I don't think we need --hard option, because
>
> - we use WQ_DYNAMIC which means that only 2 * nr_nodes threads created for the
>    whole cluster, no stress.
>
> - 'cluster snapshot load' already use WQ_DYNAMIC
Load snapshot is not the same as save snapshot.
Before loading snapshot from farm, the cluster is formatted.
This means no VM will be working when loading snapshot.
However, saving snapshot will compete with VM for IO resources.
> - more options means more confusion to users.
>
> Thanks
> Yuan