[mythtv-users] Which SystemD script?

[Stephen Worthington]

On Wed, 27 Apr 2022 18:31:04 -0500, you wrote:

>I have and existing Ubuntu 18.04/Mythtv V30 box, that works fine.  I 
>just moved, so needed to change my listing setup; figured I would 
>upgrade at the same time, so built a new box with Ubuntu 20.04 (Mate), 
>Mythtv v32, and configured with one tuner of an HDHR Connect Quatro.  
>Installation went fine but thing were very unstable, downright flaky.
>
>Found two issues; there were two master backends on the same network, 
>and there were two systemd scripts enabled on the new box. I unchecked 
>the master backend selection in setup of the existing 18.04 backend, but 
>the new box was still unstable.   The scripts were mythbackend.service 
>and mythtv-backend.service.  I disabled mythbackend.service and now it 
>works fine.
>
>I came across a recommendation to use mythtv-backend on Ubuntu, but the 
>Systemd mythbackend Configuration wiki seems to favor 
>mythbackend.service.  Which is  the preferred script?

If you have installed the Ubuntu 20.04 MythTV packages from the main
Ubuntu repositories or the fixes packages from the Mythbuntu
repository, both sets of packages use mythtv-backend.service.  It is
possible that Mate has different packages, but I do not know where
mythbackend.service will have come from.  If you want to find out,
here are instructions for finding which package a file comes from:

https://linuxhint.com/find_which_package_contains_specific_file_ubuntu/

However, if you are using networked tuners, the standard
mythtv-backend.service file does not account for this as it starts
mythtbackend when networking is first available (when the localhost
interface is up), not when networking is fully up and network tuners
are actually available.  Mythbackend tests tuners immediately after it
starts up and will not use any that do not work when tested, so it
will normally mark all network tuners as bad in that situation.  So
you need to add an override file that makes the startup of mythbackend
wait until the network tuners are actually accessible.  The usual way
to do that is to make the override file ping one of your network
tuners and get a response before it will allow mythbackend to start.
Instructions on how to do that are available on this list here:

https://lists.archive.carbon60.com/mythtv/users/625992