sudo ls -al /var/lib/lxcfs/cgroup/devices
ls: cannot access '/var/lib/lxcfs/cgroup/devices/devices.allow': Permission denied
ls: cannot access '/var/lib/lxcfs/cgroup/devices/devices.deny': Permission denied
total 0
drwxr-xr-x 2 root root 0 Sep 15 10:59 .
drwxr-xr-x 2 root root 0 Sep 15 10:59 ..
-rw-r--r-- 1 root root 0 Sep 15 10:59 cgroup.clone_children
-rw-r--r-- 1 root root 0 Sep 15 10:59 cgroup.procs
-r--r--r-- 1 root root 0 Sep 15 10:59 cgroup.sane_behavior
?????????? ? ?    ?    ?            ? devices.allow
?????????? ? ?    ?    ?            ? devices.deny
-r--r--r-- 1 root root 0 Sep 15 10:59 devices.list
drwxr-xr-x 2 root root 0 Sep 15 10:59 init.scope
-rw-r--r-- 1 root root 0 Sep 15 10:59 notify_on_release
-rw-r--r-- 1 root root 0 Sep 15 10:59 release_agent
drwxr-xr-x 2 root root 0 Sep 15 10:59 system.slice
-rw-r--r-- 1 root root 0 Sep 15 10:59 tasks
drwxr-xr-x 2 root root 0 Sep 15 10:59 user.slice