On Tue, Apr 26, 2016 at 09:19:44AM +0100, Daniel P. Berrange wrote: > On Tue, Apr 26, 2016 at 06:26:59AM +0300, Maxim Nestratov wrote: > > Hi, > > > > As far as I understand, currently there is no way to live migrate qemu VMs > > that > > have internal snapshots, because live migration works via qemu drive > > mirroring, > > which in turns mirrors only shallow block layer, effectively losing existing > > embedded > > snapshots. The problem could be fixed if we created an external delta for > > all disks with > > internal snapshots, live migrate such VMs and then auto merge them back into > > original images. That said, I would like to know very much your opinion on > > the matter > > and would also like to know if this approach is affordable. If so, I or one > > of my colleagues > > will send a pathset to fix this, otherwise what solution for this problem > > you will > > recommend? > > With modern QEMU we do the storage migration using an NBD server that > is built-in to QEMU. Now this only knows about disks that are currently > attached to the VM. I wonder though if we could simply add all the > snapshots to the running VM, but not connect them to any guest device. > > ie, we'd do blockdev_add, but would *not* do the corresponding device_add. > The built-in NBD server would then be able to export them in the same way > as the other disks. Sigh. Ignore this. You're talking internal, not external snapshots. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list