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

[MORITA Kazutaka]

At Thu, 20 Sep 2012 19:50:07 +0800,
Liu Yuan wrote:
> 
> 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.

Unfortunately, if a VM exits unexpectedly without calling bdrv_close,
the VM doesn't send SD_OP_RELEASE_VDI, so the approach doesn't look
enough to me.  If my SD_FLAG_CMD_DIRECT patch fixes the problem of
tests/044, I think it would be better to leave the coherence problem
for 0.6.0 or later.

Thanks,

Kazutaka