[Lxc-users] can't restart container without rebooting entire host, because can't delete cgroups files, tasks is 0

[Serge E. Hallyn]

A few comments:

1. To remove the directories, rmdir all descendent directories.  I'd
   think something like 'find . -type d -print0 | xargs rmdir' would
   do.
2. You can prevent this from happening by using a notify-on-release
   handler.
3. This should stop happening when lxc (soon) switches to using the
   clone-child cgroup helper instead of the ns cgroup.

-serge