[lxc-users] Problem starting trusty container on 16.04

[Fajar A. Nugraha]

On Tue, May 31, 2016 at 10:09 PM, Mike Bernson <mike at mlb.org> wrote:
> IIRC similar thing occured to me a while ago. Wrong uids in rootfs. Try
> - ls -la /var/lib/lxc/lxc-1404/rootfs (on the host)
>
> root at mike-desktop:/var/lib/lxc/lxc-1404#  ls -la
> /var/lib/lxc/lxc-1404/rootfs
> total 155
> drwxr-xr-x 21 3100000 3100000  21 May 29 23:55 .
> drwxrwx---  3 3100000 3100000   4 May 30 21:14 ..
> drwxr-xr-x  2 3100000 3100000 120 May 29 23:56 bin

> root at lxc-1404:/# ls -la /
> total 137
> drwxr-xr-x   21 root   root     21 May 30 03:55 .
> drwxr-xr-x   21 root   root     21 May 30 03:55 ..
> drwxr-xr-x    2 root   root    120 May 30 03:56 bin

I think I found the culprit. This was the first clue:
   49 ?        S      0:00 mountall --daemon

"stop mountall" and manually running that command gives:
mountall: Event failed
mount: permission denied
mountall: mount /sys/kernel/debug [3054] terminated with status 32
mountall: Filesystem could not be mounted: /sys/kernel/debug

On lxd, this is correctly mounted
# df -h /sys/kernel/debug
Filesystem      Size  Used Avail Use% Mounted on
debugfs            0     0     0    - /sys/kernel/debug

Not the case on lxc. A workround is to comment-out this line on
/lib/init/fstab, and reboot (or stop-start) the container:
none            /sys/kernel/debug         debugfs         optional
                                0 0

The appropriate fix would probably to mount it on
/usr/share/lxc/config/ubuntu.userns.conf?

Anyway, the workaround above works for me.

-- 
Fajar