[mythtvnz] New install Xubuntu 20.04

[Stephen Worthington]

On Sun, 11 Jul 2021 17:11:19 +1200, you wrote:

>I doubt this will work  unless it logs events to a log file up to the 
>point it freezes.
>
>When the system freezes it is completely locked. Alt + SysRq REISUB does 
>not work   , no keyboard interactions work (wired or wireless USB 
>keyboards.)
>
>I haven't tried a PS2 type keyboard.
>
>Timing-wise the lock-up happens within a second of the normal period a 
>shutdown requires , so the shutdown is at the brink of a successful 
>completion when it locks up.

A complete lockup like that is most likely to be a graphics driver bug
- or at least that is what it was for me on several occasions over the
years.  So if there is a later Nvidia driver in the PPA that you could
try, that might help.  I found that moving to the PPA drivers meant
that I got fixed drivers at least 6 months earlier than in the
standard repositories.  For a while after I installed my Nvidia GT
1030 and installed the later drivers for it, I was getting occasional
lockups like that on exit from playback of a recording or video, as
well as at times on shutdown.  After I went to the PPA, the frequency
of the lockups reduced substantially on one driver update, and then
went away completely two or three updates later.

>  What is the actual problem that the shutdown bug your script 
>addresses? I know there are mythbackend thread(s) that aren't 
>terminated, but what is the result of that?
>
>-paul

My shutdown commands fix was for two things - firstly, the old default
settings did not work with systemd, and secondly, you needed to do
sudo and a password to get the shutdown to start.  My fix changes the
commands to systemd ones and uses sudoers to make them work without a
password.  The mythbackendstop.sh fix is the one for the problem with
one thread of mythbackend still keeping on running when an external
shutdown request is done.  My killm script is the equivalent for
mythfrontend - the bug is in all MythTV programs, so it may be a QT
bug or something in the MythTV common code.

In MythTV v31 (also maybe v30?) the defaults for the shutdown commands
have been changed and may now work properly anyway.  I do not know
what they are as they do not overwrite existing settings when you
upgrade - I suspect that you only get them on new installs, so a new
install into a virtual PC might be the only way to find out what they
are.