On Tue, 03 Dec 2013 13:23:37 -0700 Eric Blake <eblake@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.