Re: [Qemu-devel] [PATCH 4/6] snapshot: implemention of common API to take snapshots

[Wenchao Xia]

于 2012-12-19 12:55, Dietmar Maurer 写道:
> >    OK, I think underlying storage is another level of issue, just wondering what
> > this patch miss to stop you use external tool, did you called a LVM/nexenta C
> > API in previous patch?
>
> The trick is to do thing step by step
>
> 1.) save state
> 2.) create internal snapshots
> 3.) call external tools to create snapshots
> ...
>
> 1 and 2 is done inside qemu, 3 is done from the management tool.
>
> You use qmp_transactions, which makes that impossible.

  There is simple HMP/QMP API for 2), in patch 5,6, not in the
form of qmp_transaction, simply blkdev_snapshot() form.
1) will be added later, which have some issue need to solve now.

qmp_transaction() or blkdev_snapshot() call the common API
in this patch. "common API" in this patch is for qemu not user,
it is hidden, maybe that caused misunderstanding.


--
Best Regards

Wenchao Xia