To continue from the previous post, I just noticed this... Aug 23 16:50:04 mbox audit[2550]: AVC apparmor="DENIED" operation="mount" info="failed type match" error=-13 profile="lxc-container-default" name="/sys/fs/cgroup/" pid=2550 comm="systemd" flags="ro, nosuid, nodev, noexec, remount, strictatime"