Need help debugging shutdown issues

[Nikolaus Rath]

Nikolaus Rath <Nikolaus-BTH8mxji4b0 at public.gmane.org> writes:
> On 11/06/2014 07:15 PM, Michael Biebl wrote:
>> Am 07.11.2014 um 02:32 schrieb Nikolaus Rath:
>>> Michael Biebl <biebl-8fiUuRrzOP0dnm+yROfE0A-XMD5yJDbdMReXY1tMh2IBg at public.gmane.org> writes:
>> 
>> 
>>>> Try running "systemctl stop networking.service" before you
>>>> shutdown/reboot. This service seems to be hanging in "ifdown -a".
>>>> Might be dhclient or ifdown.d hook script causing a dead lock.
>>>
>>> I tried that, but it still hangs. 
>> 
>> Ok, please include, again, the output of systemctl status, list-jobs
>> and ps aux from the debug shell so we see which job systemd is blocking
>> on and which processes are running.
>
> Well, that's the problem. If I'm able to access the debug shell, then
> the system reboots fine. If the reboot is frozen, I don't seem to be
> able to switch to tty9 anymore either.
>
> I also tried running an sshd process in the debug shell (to see if I can
> still reach the system remotely when it hangs), but the connection got
> closed when I ran the systemctl command - why might that be? I had hoped
> that processes spawned from the debug-shell would not get killed?
>
> (I first stopped the regular ssh server and networking using systemctl,
> then manually brought up networking in the debug shell as well).

I now managed to get the logs from the
/lib/systemd/system-shutdown/debug.sh script (the problem with this was
that I remounted too late):

$ cat /lib/systemd/system-shutdown/debug.sh 
#!/bin/sh
mount -o remount,rw /
exec > /shutdown.log
exec 2>&1
echo stdout
echo stderr >&2
dmesg
systemctl list-jobs
systemctl status
echo done
mount -o remount,ro /

I uploaded the output from a failed reboot to

https://dl.dropboxusercontent.com/u/11545826/shutdown.log


Best,
-Nikolaus

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