From the POV of libvirt uses though, there has been one annoyance with

Some folks may be aware of the SpecVirt benchmark, where KVM is giving the competition something to worry about :-) http://www.spec.org/virt_sc2010/results/ the previously submitted results though, in that they have been invoking the KVM command line directly. This has made it harder for people who are deploying KVM using libvirt to replicate the optimal configurations. I'm pleased to be able to point out that the latest result published for KVM by IBM has in fact been done using libvirt! You can clearly see how the guests are being configured with libvirt and the results demonstrate that using libvirt to manage KVM does not involve sacrificing any of the performance that KVM offers: http://www.spec.org/virt_sc2010/results/res2011q4/ This can only continue to get better as our communities work together to add more performance related features to both libvirt and KVM :-) 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 :|