On Tue, Apr 10, 2012 at 01:17:44PM -0400, Laine Stump wrote: > On 04/09/2012 11:52 PM, Eric Blake wrote: > > The new block copy storage migration sequence requires both the > > 'drive-mirror' action in 'transaction' (present if the 'drive-mirror' > > standalone monitor command also exists) and the 'drive-reopen' monitor > > command (it would be nice if that were also part of a 'transaction', > > but the initial qemu implementation has it standalone only). > > > > Furthermore, qemu 1.1 will be adding 'block_job_cancel' as an > > asynchronous command, but an earlier implementation (that supported > > only the qed file format) existed which was synchronous only. If > > 'drive-mirror' is added in time, then we can safely use 'drive-mirror' > > as the witness of whether 'block_job_cancel' is synchronous or > > asynchronous. > > > > As of this[1] qemu email, both commands have been proposed but not yet > > incorporated into the tree; in fact, the implementation I tested with > > has changed to match this[2] email that suggested a mandatory > > 'full':'bool' argument rather than 'mode':'no-backing-file'. So there > > is a risk that qemu 1.1 will have yet another subtly different > > implementation. > > [1]https://lists.gnu.org/archive/html/qemu-devel/2012-03/msg01524.html > > [2]https://lists.gnu.org/archive/html/qemu-devel/2012-04/msg00886.html > > > None of this gives me warm fuzzies :-/ Based on previous experience, my suggestion is that we do *not* merge any of this new libvirt API work, until the QEMU stuff has actually been accepted into their git master. The previous block streaming stuff is a nice history lesson in what happens when we merge stuff in libvirt before QEMU has agreed their final design :-( 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