[libvirt-users] libvirt possibly ignoring cache=none ?

Hi, I have an instance with 8G ram assigned. All block devices have cache disabled (cache=none) on host. However, cgroup is reporting 4G of cache associated to the instance (on host) # cgget -r memory.stat libvirt/qemu/i-000009fa libvirt/qemu/i-000009fa: memory.stat: cache 4318011392 rss 8676360192 ... When I drop all system caches on host.. # echo 3 > /proc/sys/vm/drop_caches # ..cache associated to the instance drops too. # cgget -r memory.stat libvirt/qemu/i-000009fa libvirt/qemu/i-000009fa: memory.stat: cache 122880 rss 8674291712 ... Can somebody explain what is cached, if there is cache=none everywhere ? Thanks, Brano Zarnovican PS: versions: Scientific Linux release 6.4 (Carbon) kernel-2.6.32-358.11.1.el6.x86_64 qemu-kvm-0.12.1.2-2.355.el6_4.5.x86_64 libvirt-0.10.2-18.el6_4.5.x86_64