There was a thread about this in December: http://www.mail-archive.com/openstack@lists.launchpad.net/msg06296.html I think that thread is saying that if you follow the official documentation for configuring live migration, but use --multi_host, then migration will not actually work. If that is right, is there (or will there be) an officially documented way to to this, either for diablo or essex? -David