Bug#792761: UX issue, handling of endless shutdown loops

[Felipe Sateler]

On 20 July 2015 at 03:48, Eduard Bloch <edi at gmx.de> wrote:
> Hallo,
> * Felipe Sateler [Sun, Jul 19 2015, 03:14:11PM]:
>> So, we have 2 issues:
>>
>> 1. Your system is not shutting down
>> 2. Systemd is not telling you enough to discover what is wrong.
>>
>> I'm afraid 2 is really an upstream issue and not an integration issue.
>> Could you please file that bug upstream?
>
> Maybe... I will give it a try tonight. However I am sceptical regarding
> "productive" communication with upstream.

Great, let us know when you have filed a bug upstream.

>
>> We can try to help debug number 1, though, and there may be a real
>> integration bug. Please see the shutdown section in the upstream
>> wiki[1]; in particular, starting the debug shell before shutting down
>
> The thing is, the issue is not reproducible. It might happen once a
> month, and then not appear for many months. And you don't want to enable
> all the debug machinery all the just in case. The thing needed is the
> minimum control mechanism in place just when the problem occurs.
>
> And when it happens for the first time, it's too late to active the
> debug shell.

You can enable debug-shell.service, so that when it happens, you have
the shell on tty9. I don't know if this can be started up on demand
(specially if it is that late in the shutdown sequence).

>
>> and switching to it when the shutdown hangs should let you query the
>> journal to find out issues.
>>
>> Note that if you enabled persistent journal logging you can maybe
>> still get the info from the journal: journalctl -b -<number of boots
>> since the last hang>
>
> Says that it cannot find an id. Checked:
>
> $ sudo journalctl --list-boots
> -1 39f59f8ebdd644f39aeb46b67eef9bff Sa 2015-07-18 09:12:05 CEST—Mo 2015-07-20 08
>  0 39f59f8ebdd644f39aeb46b67eef9bff Mo 2015-07-20 08:39:43 CEST—Mo 2015-07-20 08
>
> No idea what happened to the logs.

Do you have persistent logging enabled? I think you do not. Please
follow the instructions of the README.Debian if you want to enable it.

-- 

Saludos,
Felipe Sateler