[Libvir] Snapshots for Xen and KVM

[John Levon]

On Tue, Mar 11, 2008 at 03:43:51PM +0000, Richard W.M. Jones wrote:

> On Tue, Mar 11, 2008 at 12:54:37PM +0200, Gabriel Kaufmann wrote:
> > Does anyone knows if Xen and KVM support snapshots (regardless if
> > Libvirt provides the API for them).
> 
> It's currently on the Xen to-do list, but apart from some research
> papers I'm not aware of them implementing it.  Perhaps recently.
> Checkpointing is tricky to get right because you have to take a
> snapshot of the memory and disk at exactly the same moment.
> 
> Note that neither Xen's live migration nor the domain save features
> are real checkpoints, because they both only consider the memory.

Why would Xen itself be at all concerned with snapshotting the disk?
AIUI, there's hooks in xend so you just plug in your disk snapshotting
(ZFS, LVM, vmdk, whatever) to that.

regards
john