Jessie sans systemd en hôte + wheezy en guest = « Could not find writable mount point for cgroup hierarchy 9 while trying to create cgroup. »

Solution :
« According to https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=773421 it was a debian bug, because lxc there was build without cgmanager support. So if you use unstable\testing just install the latest package, on stable use the way mentioned above [ apt-get install cgroupfs-mount ]. »