Thank you very much, Eric!
So do you mean, if I turn on libvirt debugging to trace QMP/agent commands,
I can find the pause and thaw functions in the source code, is it right ?
and is there any way that I freeze and thaw outside guest agent via command
line? or profiling tools suggest for freeze and thaw in guest agent?
thanks a lot!
Best,
Yuanzhen
On Wed, Jul 16, 2014 at 5:18 PM, Eric Blake <ebl...@redhat.com> wrote:
> On 07/16/2014 03:13 PM, Yuanzhen Gu wrote:
> > Hi folks,
> >
> >
> > I am going to make a patch, and need to find the pause and thaw(restore)
> > function before and after taking Live QEMU Snapshot respectively.
>
> Libvirt has the ability to do just that, when taking external disk-only
> snapshots. You can turn on libvirt debugging to trace what QMP/agent
> commands are sent during the overall snapshot operation.
>
So do you mean, if I turn on libvirt debugging to trace QMP/agent
commands, I can find the pause and thaw functions in the source code, is it
right ?
>
> >
> >
> > Basically, I'm using # (qemu) snapshot_blkdev <blockX>
> > <snapshot-file><format> taking snapshot,
> > http://wiki.qemu.org/Features/Snapshots my profile tool didn't work
> when
> > giving command inside QMP.
> >
> >
> > Does anyone know how to find the pause (freeze) and restore(thaw)
> function
> > before and after taking snapshot? Or anyway using snapshot_blkdev command
> > outside QEMU console? Thanks a lot in advance!
>
> You have to coordinate multiple commands: freeze to the guest agent,
> then snapshot to QMP, then thaw to the guest agent.
>
> --
> Eric Blake eblake redhat com +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
>
>
