Tvheadend

You should also look to the kernel log. It appears that the DVB driver hangs for a reason.

I appologize for my ignorance. Are you referring to the output of "dmesg" or is there a specific file that contains the information you are referring to? If so, what file should I look at/post in order to find the problem?

Sorry for the long delay. After researching and trying to get the kernel log files working in libreelec I finally decided that I would be better off with moving to ubuntu server 18.04. I installed the latest stable version of tvheadend (4.2.8) and had a couple of the above descibed situations. However when looking at kern.log or syslog I did not find anything that looked very specific. I will do some more testing and logging and upload the results here. However I do have some more questions, that might help me to collect the right information.
Is there anything I need to enable in tvheadend or in the kerel to collect all relevant information? Would you recommend to upgrade tvheadend to the latest (unstable) version?

One more piece of information: Once I experience the situation described above I noticed that tvheadend does not report any incoming data from the streams, at the same time I have many processes (one per each of the 8 receivers) that each creates a high CPU load of 20-40% on each. How can I clearly identify if the kernel driver is really causing the problem and if so, should I then get into contact with Digital Devices?

Right now the situation is quite frustrating because the problem happened while trying to do recordings I only noticed that it did not work afterwards. I also did not find a solution to "reanimate" things other than rebooting. Stopping and starting the tvheadend service is not sufficient. Even unloading and reloading the tv card kernel modules (ddbridge cxd2099 dvb_core) after and before stoping and starting tvheadend does not resove the problem as far as I can tell. Does that help to find the location of the problem. Since I'm traveling right now I cannot currently send or upload any log files.

Definitely upgrade to unstable, at this point that's actually very stable and might already solve your problem.

Most likely you're encountering a driver issue or the card crashed. If a restart of tvheadend doesn't fix the issue you can be almost 100% sure it's not a tvheadend issue.

Hello,

here is a short update to how things progressed. After a lot of debugging (big thanks to Andreas McPherson from the Digital Devices Support Team) Digital Devices offered to look into the tuner card for a potential HW defect. In parallel I also talked to the seller of the mainboard and replaced it with a new one (still the same type though). As Digital Devices didn't want me to wait even longer for a working system they replaced my card with a brand new one!!!
The new card on the new mainboard now work without any issue! I don't know though whether the problem was caused by the tuner card or the mainboard, nevertheless I'm now very happy in particular Digital Devices offered great support!

Bernd