libvirt users - Aug 2014 - libvirt external disk-only snapshot will pause the VM?

Hello folks,

If I give command to take external disk-only live snapshot, such as
# virsh snapshot-create-as vm1 snapshot_vm1 --disk-only

will the guest OS be paused or suspend while the snapshot being taken?

Thanks very much!


Best,
Yuanzhen

On 08/05/2014 03:54 PM, Yuanzhen Gu wrote:
> Hello folks,
> 
> If I give command to take external disk-only live snapshot, such as
> # virsh snapshot-create-as vm1 snapshot_vm1 --disk-only
> 
> will the guest OS be paused or suspend while the snapshot being taken?
The guest will temporarily pause, but the time that it remains paused
will be a fraction of a second.  In practice, it is no longer than the
time that the guest is paused when doing live migration.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

Thanks very much Eric!  This is exactly what I guessed, I just wondering
where I could find this piece of code and control the the pause time of
guest, while the snapshot being taken?  thanks !

Best,
Yuanzhen


On Tue, Aug 5, 2014 at 6:30 PM, Eric Blake <eblake@redhat.com> wrote:
> On 08/05/2014 03:54 PM, Yuanzhen Gu wrote:
> > Hello folks,
> >
> > If I give command to take external disk-only live snapshot, such as
> > # virsh snapshot-create-as vm1 snapshot_vm1 --disk-only
> >
> > will the guest OS be paused or suspend while the snapshot being taken?
>
> The guest will temporarily pause, but the time that it remains paused
> will be a fraction of a second.  In practice, it is no longer than the
> time that the guest is paused when doing live migration.
>
> --
> Eric Blake   eblake redhat com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
>
>