Following section indicates that CPU tuning with <period> and <quota> tags are only supported for QEMU http://libvirt.org/formatdomain.html#elementsCPUTuning I see this commit in libvirt.git: commit d9724a81b3c53a40f45bf76067a976cce73ed278 Author: Daniel P. Berrange <berrange(a)redhat.com&gt; Date: Thu Nov 10 12:16:26 2011 +0000 Add support for CPU quota/period to LXC driver and the code seems to be included in libvirt-0.9.10-21.el6. I have not had a chance to try on latest libvirt yet, but is it just that the CPUTuning section on the above wiki needs an update ?