[Lxc-users] failed to create pty #0

[C Anthony Risinger]

On Mon, Sep 20, 2010 at 4:29 AM, lxc at jelmail.com <lxc at jelmail.com> wrote:
> Hi Daniel,
>
> I have tracked down this issue somewhat. It seems to be caused by shutting
> down a container (not by lxc-stop) and is caused by the rc.shutdown script
> present in Arch Linux.
>
> I don't know what specifically causes the problem because I haven't had
> time to investigate but I do know that it's fixed by removing everything
> from rc.shutdown onwards from the line containing "stat_busy “Saving System
> Clock”" as suggested on lxc.teegra.net (I had done this on a prior
> container but missed this step on a new one which is why the problem only
> started happening recently).
>
> So something in that shutdown file has the capacity to disable the host's
> ability to start further containers and also disable the ability to ssh
> into already running ones (thankfully, lxc-console still worked).

i also use arch on all my systems, and although i have not used lxc in
awhile, i ran into this issue when i did; this may not be your
problem, but it might be useful to others.

when using the 'newinstance' mount opt to devpts, you have to ensure
that /dev/ptmx is a symlink to /dev/pts/ptmx.  this is even more
critical if your host is also using 'newinstance' (as mine was), since
the legacy, kernel bound/single-instance ptmx will not exist and all
pty allocations will fail.  at one point, one of the init scripts (the
startup one IIRC) was overwriting my /dev/ptmx symlink with an actual
ptmx node, which subsequently was causing the same error you are
receiving.

my problem was persistent however; once /dev/ptmx was changed, all
allocations would fail until i repaired the symlink.

C Anthony