Hi, To control memory with libvirt-lxc you need to have the memory controller and swap account controllers active. This means (on Debian) adding: cgroup_enable=memory swapaccount=1 to GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub doing sudo update-grub and then rebooting.
You are probably seeing lots of messages in your logs like: Failed to open file '/sys/fs/cgroup/memory/machine/lxc-41320-containername.libvirt-lxc/memory.memsw.usage_in_bytes in your logs. Peter C -- Dr Peter Chubb Tel: +61 2 9490 5852 http://ts.data61.csiro.au/ Trustworthy Systems Group Data61 (formerly NICTA)