On Wednesday 10 June 2009, Michael S. Tsirkin wrote: > On Wed, Jun 10, 2009 at 05:46:03PM +0100, Paul Brook wrote: > > > > If you can't create an identical machine from scratch then I don't > > > > consider snapshot/migration to be a useful feature. i.e. as soon as > > > > you shutdown and restart the guest it is liable to break anyway. > > > > > > Why is liable to break? > > > > A VM booted on an old version of qemu and migrated to a new version will > > behave differently to a the same VM booted on a new version of qemu. > > It will behave identically. That's what the patch does: discover > how did the device behave on old qemu, and make it behave the same way > on new qemu. You're missing the point. After doing a live migration from old-qemu to new- qemu, there is no snapshot to load. We need to be able to shutdown the guest, kill qemu (without saving a snapshot), then start qemu with the exact same hardware. If we can't start a new qemu with the same hardware configuration then we should not be allowing migration or loading of snapshots. Paul -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
