Re: [Qemu-devel] QCOW2 multiple disk (not VM) snapshots

[Anthony Liguori <anthony@codemonkey.ws>]

Kevin Wolf wrote:
> Hi Mike,
>
> Mike Sun schrieb:
>   
>> For a research project, we've been doing a bit of hacking with Xen and
>> utilize QCOW disk images as our VBDs. One intriguing thing about the
>> QCOW2 format was support for multiple disk snapshots. Unfortunately,
>> it seems from what I've been able to glean that support for multiple
>> snapshots within a QCOW2 image is really only supported by QEMU's VM
>> snapshot feature. Since I'm using Xen and only use QCOW2 disk images,
>> I was wondering if there was any way from a tool such as 'qemu-img' to
>> take snapshots of the QCOW2 disk image only and not through the
>> general QEMU VM snapshot?
>>     
>
> You can try the attached patch to qemu-img. I had it already for list,
> delete and apply (as that's what I've needed so far), and I just added
> create to it to make it complete. However, I didn't test it more than
> making sure that it compiles and a new snapshot is listed afterwards.
>
> If you're interested in having real snapshots with Xen, i.e. basically a
> combination of xm save/restore and qemu-img snapshot, I also have some
> patches to do that. They have quite a few dependencies, though, so they
> are not yet upstream.
>   

Care to resubmit with a proper Signed-off-by line?  Seems like a useful 
feature.

Regards,

Anthony Liguori

> Kevin
>