[lxc-users] Containers not shutting down

[Mark Constable]

Ubuntu 15.04 w/ btrfs.

Since the past 2 days of updates I notice my lxc and lxd containers just hang
when trying to shut them down, consequently rebooting my laptop requires a
hard power button reset (so far btrfs on a SSD has survived). Also my main
system privileged container does not provide any output for free and top and
even an apt-get upgrade just hangs (hence I can't get systemd 219-4ubuntu7).

The above is FWIW but this one I am not sure where to start looking to track
down how to fix this?... any hints appreciated.

Mar 20 15:36:30 sysadm.lan systemd[1]:
  Failed to reset devices.list on
  /lxc/sysadm.lan/system.slice/courier-authdaemon.service: Permission denied

ie; where is /lxc/ ?

If I try a hunch and check where lxcfs is mounted on the host a listing of
that mount point also just hangs...

~ mount | grep lxc
lxcfs on /var/lib/lxcfs type fuse.lxcfs (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other)

~ ll /var/lib/lxcfs
^C
[hangs]

As far as I can remember this started about Wed 18th March.