On Tue, 03 Dec 2013 13:23:37 -0700
Eric Blake <eblake(a)redhat.com> wrote:
On 12/03/2013 12:37 PM, Michael Mol wrote:
> A pity. Thin provisioning would be (as I see it) the first step to
> whole-VM snapshots as found in systems like VMWare ESX. I'd love to
> be able to pull that off using Linux/QEMU/KVM. Or at least be able
> to snapshot a running VM's disk to be able to pull backups off the
> snapshot without interrupting service in the VM guests.
Ah, but you already CAN do that. Libvirt external snapshots (since
libvirt 1.0.5, or even earlier if you don't care about machine state
but just disk state) coupled with qemu 1.3 or newer is perfectly able
to create qcow2 chains such that you can do a backup of the snapshot
without any downtime to the guest. Admittedly, keeping things optimal
so that the qcow2 chain doesn't grow without bounds is a bit harder
problem, and qemu 1.7 has added some new functionality not yet
integrated into libvirt to make life easier for taking snapshots
without having to track the cleanup efforts. But your claim that
libvirt can't do online backups the way ESX can aren't quite true :)
Excellent to hear!
Where can I find out more about how to handle cleanup? I don't need an
automatic backup process requiring manual cleanup.