Re: [Qemu-devel] Block Migration and CPU throttling

[Dr. David Alan Gilbert]

* Peter Lieven (address@hidden) wrote:
> Am 19.09.2017 um 16:38 schrieb Dr. David Alan Gilbert:
> > * Peter Lieven (address@hidden) wrote:
> > > Hi,
> > > 
> > > I just noticed that CPU throttling and Block Migration don't work 
> > > together very well.
> > > During block migration the throttling heuristic detects that we obviously 
> > > make no progress
> > > in ram transfer. But the reason is the running block migration and not a 
> > > too high dirty pages rate.
> > > 
> > > The result is that any VM is throttled by 99% during block migration.
> > Hmm that's unfortunate; do you have a bandwidth set lower than your
> > actual network connection? I'm just wondering if it's actually going
> > between the block and RAM iterative sections or getting stuck in ne.
> 
> It happens also if source and dest are on the same machine and speed is set 
> to 100G.

But does it happen if they're not and the speed is set low?

Dave

> Peter
> 
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK