On Tue, Nov 12, 2013 at 08:14:11PM +0800, Zheng Sheng ZS Zhou wrote:
Hi all,
Recently QEMU developers are working on a feature to allow upgrading a live QEMU instance to a new version without restarting the VM. This is implemented as live migration between the old and new QEMU process on the same host [1]. Here is the the use case:
1) Guests are running QEMU release 1.6.1. 2) Admin installs QEMU release 1.6.2 via RPM or deb. 3) Admin starts a new VM using the updated QEMU binary, and asks the old QEMU process to migrate the VM to the newly started VM.
I think it will be very useful to support QEMU live upgrade in libvirt. After some investigations, I found migrating to the same host breaks the current migration code. I'd like to propose a new work flow for QEMU live migration. It is to implement the above step 3).
How does it break migration code ? Your patch below is effectively re-implementing the multistep migration workflow, leaving out many important features (seemless reconnect to SPICE clients for example) which is really bad for our ongoing code support burden, so not something I want to see. 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 :|