[sheepdog] [PATCH] tests: add a test to test vdi snapshot functionality concurrently

[Liu Yuan]

On 09/20/2012 12:52 AM, MORITA Kazutaka wrote:
> Well, I guess it's a good time to fix this kind of coherence problem
> of object cache.  I think the root cause here is that sheep doesn't
> release object cache even after the same VM is opened on another node.
> Does below patch solve this problem?  IIUC, this patch fixes the
> inconsistency problem even if collie/qemu uses a writeback mode.
> 

Can we capture VM release signal? If so, it is very easy to implement this semantics.

> To make object cache meet block device semantics, we should flush
> caches rather than deleting them.  However, it's a bit difficult to
> implement it without a race condition, so I think it's better to leave
> it for future work.

Object cache already support a API to flush before deletion. This is not the problem.

Thanks,
Yuan