Re: [Qemu-devel] Network Migration in QEMU during Live Migration

[Gary R Hook]

On 2/4/15 2:02 PM, Eric Blake wrote:
> On 02/04/2015 12:01 PM, Azizul Hakim wrote:
> > Does QEMU support network migration so that the migration process is
> > transparent to users? For example if my VM has a web server, I would like
> > my user still be able to send request to the server after the migration
> > process is completed. But since migration causes a change of the physical
> > machine, the IP address is different. So how do I achieve this? I
> > understand that I've to create bridge network. What other things do I've to
> > take care off? Is it possible at all?
>
> The IP address of the host is different, but the IP address seen by the
> guest is the same.  Live migration has been possible for several years
> with qemu, and people do it all the time.  The guest sees very minimal
> downtime (a few milliseconds).  If you use a higher-layer software, like
> libvirt, then triggering a live migration of a guest is quite easy.

What he said. The guest doesn't know, doesn't care, and doesn't change 
its network configuration; external connections are maintained. Only the 
host upon which the guest runs changes, and that is kind of irrelevant 
from a guest perspective.

--
Gary R Hook
Senior Kernel Engineer
NIMBOXX, Inc