[mythtv-users] udev and systemd requirements for MythTV on Ubuntu 20.04?

Mike Bibbings mike.bibbings at gmail.com
Mon Jul 27 15:54:01 UTC 2020

On 27/07/2020 15:43, James Abernathy wrote:
> I'm doing some planning for moving from MythTV v31 on Ubuntu 18.04 to 
> MythTV v31 on Ubuntu 20.04.  There are a lot of considerations, like 
> my current system using MariaDB and the current issue regarding that 
> on Ubuntu 20.04.
> However, my concerns today are related to udev rules and systemd 
> overrides.
> On my 18.04 system, I have one udev rule related to mythtv; 
> 99-mythbackend.rules
> SUBSYSTEM=="video4linux", TAG+="systemd"
> SUBSYSTEM=="dvb", TAG+="systemd"
> SUBSYSTEM=="firewire", TAG+="systemd"
> When I installed mythtv v31 on a virtual machine of Ubuntu 20.04, this 
> file was not there. I probably created it myself because of the 
> Hauppauge WinTV HD Quad PCIe tuner card I was using.
> So is this still necessary for Ubuntu 20.04 and mythtv v31?
> Also,  on my current system I have an override file in 
> /etc/systemd/system/mythtv-backend.service.d/ythtv-backend-override.conf:
> [Unit]
> Wants=dev-dvb-adapter0-frontend0.device
> After=dev-dvb-adapter0-frontend0.device
> Wants=dev-dvb-adapter1-frontend0.device
> After=dev-dvb-adapter1-frontend0.device
> Wants=dev-dvb-adapter2-frontend0.device
> After=dev-dvb-adapter2-frontend0.device
> Wants=dev-dvb-adapter3-frontend0.device
> After=dev-dvb-adapter3-frontend0.device
> After=NetworkManager-wait-online.service
> I figure this is also related to the Hauppauge card and also my 
> HDHomerun tuner.
> Again I think I did this back with mythtv29 and it's stayed through 
> the upgrades to v31.
> Do I need any of this in mythtv v31 on Ubuntu 20.04?
> On the Ubuntu 20.04 test virtual machine I have only the HDHR tuner 
> and it works fine but I have no udev rules or systemd override file.
> Thoughts?
> Jim A

Yes, you did setup those entries for your PCI-e tuner, they make sure 
mythtvbackend starts only when the card has been fully setup during boot.

For network tuners e.g. HDHOMERUN there is a different problem in that 
mythtv-backend can start before networking is fully established see 


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