[mythtvnz] New install Xubuntu 20.04

[Stephen Worthington]

On Sun, 11 Jul 2021 14:54:52 +1200, you wrote:

>It seems I spoke too soon.
>
>If I let the mythwelcome screen time out when idle (300 secs) the system 
>shutsdown and freezes on the splash screen.
>
>btw. I ran the mythtv-systemctl-helper commands from the terminal and 
>there was no prompt for a password and they worked fine.
>
>I'm not too fussed about it - my current system has run 16.04 fine since 
>2017 with no mythtv-systemctl-helper script.
>
>I don't believe it has anything to do with Mythwelcome - as I said 
>previously,it was doing this lock up before I enabled Mythwelcome when 
>the BE idle timeout shut the system down.
>
>I use MythTV Control Panel to set up the system , maybe that has 
>something to do with it.

I would doubt that.  MCC just does the same things as you would have
to do manually without it.

>-Paul

If you want to be able to see what is happening when a shutdown does
not work, you can enable the systemd debug shell.  This is a console
session on Ctrl-Alt-F9 that is started very early in the boot process
and stopped very late during shutdown.  It is a root login that does
not require you to actually log in as the login code is not available
when it is started, so it is a huge security hole when enabled:

sudo systemctl enable debug-shell.service

or put this on the kernel command line:

systemd.debug-shell=1

Then make the bad shutdown happen and go to Ctrl-Alt-F9 and see if it
is still running.  If it is, you can do commands like:

systemctl list-jobs

to see what is still running and holding up the shutdown.  You can
then try giving kill -9 commands to things or unmounting things to see
if the shutdown will then complete.

If the Ctrl-Alt-F9 session was able to be used, then it is very likely
that the system would eventually shut down - but it could take a very
long time (> 20 minutes), as it is likely going to be waiting on a
series of very long timeouts.

Do not forget to disable the debug shell when you have finished using
it:

sudo systemctl disable debug-shell.service