tfcyundlim dehasawzdg
2016-Apr-04 15:57 UTC
[libvirt-users] Can you get page dirtying information on non-migrating VMs?
Hello everyone, I've been looking through the libvirt API to get information about memory page dirtying of VMs. I need these to aid decisions on which VM to migrate. The only thing I found is virDomainGetJobStats() with VIR_DOMAIN_JOB_MEMORY_DIRTY_RATE but that only works when a migration is already running. Is there a way to get information on VMs which are not already migrating? Thanks and best regards, Dave
Daniel P. Berrange
2016-Apr-04 16:01 UTC
Re: [libvirt-users] Can you get page dirtying information on non-migrating VMs?
On Mon, Apr 04, 2016 at 05:57:43PM +0200, tfcyundlim dehasawzdg wrote:> Hello everyone, > > I've been looking through the libvirt API to get information about > memory page dirtying of VMs. I need these to aid decisions on which VM > to migrate. > The only thing I found is > > virDomainGetJobStats() > > with > > VIR_DOMAIN_JOB_MEMORY_DIRTY_RATE > > but that only works when a migration is already running. > Is there a way to get information on VMs which are not already migrating?No, IIUC, page dirtying is only enbled by QEMU while migrating because it has non-neglible performance impact on the guest. Regards, 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 :|