Re: [Xen-devel] [PATCH RFC] Live migration for VMs with QEMU backed local storage

[Wei Liu <wei.liu2@xxxxxxxxxx>]

On Thu, Jun 29, 2017 at 03:34:37PM +0100, Roger Pau Monné wrote:
> On Thu, Jun 29, 2017 at 02:56:55PM +0100, Wei Liu wrote:
> > On Thu, Jun 29, 2017 at 09:33:07AM -0400, Bruno Alvisio wrote:
> > > Thanks Wei. Currently it is started after the memory is streamed from
> > > source to destination (for migration) and the booting functions are
> > > completed.I was going to ask to the list if there is a specific reason the
> > > QEMU process needs to be started at that point.
> > 
> > I _think_ it is because we don't want QEMU to touch guest memory / state
> > too early. Note I haven't checked the code. Do ask on the list if you
> > aren't sure.
> 
> I would have thought that's because you need the QEMU state, and
> that's not saved until the guest on the other end is paused (ie:
> rather at the end of the memory copy).
> 

This is also a plausible cause. This can also be worked around I think.
The principle is same -- start QEMU first and load state later. But then
this begs the question how you can handle the mirroring and state
transfer concurrently.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel