Re: [Qemu-devel] Question about dirty page statistics for live migration

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Li Qiang (liq3ea@gmail.com) wrote:
> Hello Dave, Juan and all,
> 
> It is useful to get the dirty page rates in guest to evaluate the guest
> loads
> so that we can make a decide to live migrate it or not. So I think we can
> add a on-demand qmp for showing the dirty page rates.
> 
> I found someone has done this work in here:
> -->https://github.com/grivon/yabusame-qemu-dpt
> and here:
> https://github.com/btrplace/qemu-patch
> 
> But seems not go to the upstream.
> 
> I want to know your opinions about adding this qmp.

Something like that could be good;  one easy idea we had was
a 'migrate null:' uri and then you would use most of the existing
migration code to do the measurement; you would only have to
add a dummy file backend, and something to stop the migration ever
terminating (maybe just set the downtime very low).


Dave


> Thanks,
> Li Qiang
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK