[Solved] Working v29.1 suddenly ceases to record or get Live TV

[pinnerite]

I have been running Mythtv Version 29.1-13 for several weeks without issues.
It was recording successfully two days ago but failed last night.

On checking I found that I could not get live TV either.
The logs suggested that permissons might be the problem but they were fine.

dmesg confirmed that the tuner drivers had loaded correctly.
The backend status is fine until a frontend is started. e.g.

/bin/systemctl status mythtv-backend.service

Code: Select all

● mythtv-backend.service - MythTV Backend
   Loaded: loaded (/lib/systemd/system/mythtv-backend.service; enabled; vendor preset: enabled)
   Active: active (running) since Wed 2020-01-08 18:11:36 GMT; 46min ago
     Docs: https://www.mythtv.org/wiki/Mythbackend
 Main PID: 7209 (mythbackend)
    Tasks: 39 (limit: 4915)
   CGroup: /system.slice/mythtv-backend.service
           └─7209 /usr/bin/mythbackend --quiet --syslog local7

Jan 08 18:52:06 origen.asandco mythbackend[7209]: mythbackend[7209]: I MythSocketThread(115) mainserver.cpp:7674 (connectionClosed) Playback sock(55de60db97f
Jan 08 18:52:30 origen.asandco mythbackend[7209]: mythbackend[7209]: I Scheduler scheduler.cpp:2356 (HandleReschedule) Reschedule requested for MATCH 0 0 0 2
Jan 08 18:52:30 origen.asandco mythbackend[7209]: mythbackend[7209]: I Scheduler scheduler.cpp:2469 (HandleReschedule) Scheduled 45 items in 0.0 = 0.01 match
Jan 08 18:54:27 origen.asandco mythbackend[7209]: mythbackend[7209]: I Scheduler scheduler.cpp:2356 (HandleReschedule) Reschedule requested for MATCH 0 1 0 2
Jan 08 18:54:27 origen.asandco mythbackend[7209]: mythbackend[7209]: I Scheduler scheduler.cpp:2469 (HandleReschedule) Scheduled 45 items in 0.0 = 0.01 match
Jan 08 18:54:27 origen.asandco mythbackend[7209]: mythbackend[7209]: I TVRecEvent tv_rec.cpp:3665 (TuningFrequency) TVRec[2]: TuningFrequency
Jan 08 18:54:59 origen.asandco mythbackend[7209]: mythbackend[7209]: I TVRecEvent tv_rec.cpp:3665 (TuningFrequency) TVRec[1]: TuningFrequency
Jan 08 18:57:37 origen.asandco mythbackend[7209]: mythbackend[7209]: I MythSocketThread(116) mainserver.cpp:7674 (connectionClosed) Monitor sock(55de610066b0
Jan 08 18:57:37 origen.asandco mythbackend[7209]: mythbackend[7209]: I MythSocketThread(117) backendcontext.cpp:102 (SetFrontendDisconnected) BackendContext:
Jan 08 18:57:37 origen.asandco mythbackend[7209]: mythbackend[7209]: I MythSocketThread(117) mainserver.cpp:7674 (connectionClosed) Playback sock(55de60ed5e0

However after a remote frontend was started, the backend status changed. After is was terminated, it change again. The 3rd and 4th significant lines of the final block below show the result.

Code: Select all

Jan 08 19:05:00 origen.asandco mythbackend[7209]: mythbackend[7209]: I Scheduler scheduler.cpp:2469 (HandleReschedule) Scheduled 45 items in 0.0 = 0.01 match
Jan 08 19:05:01 origen.asandco mythbackend[7209]: mythbackend[7209]: I TVRecEvent tv_rec.cpp:3665 (TuningFrequency) TVRec[1]: TuningFrequency
Jan 08 19:07:22 origen.asandco mythbackend[7209]: mythbackend[7209]: E DVBRead mpeg/mpegstreamdata.cpp:340 (AssemblePSIP) MPEGStream[1](0x7f3a2419fa60): Erro
Jan 08 19:09:17 origen.asandco mythbackend[7209]: mythbackend[7209]: E DVBRead mpeg/mpegstreamdata.cpp:340 (AssemblePSIP) MPEGStream[1](0x7f3a2419fa60): Erro

Afrer reloading the front end, the first four lines changed to this:

Code: Select all

Jan 08 19:16:46 origen.asandco mythbackend[7209]: mythbackend[7209]: E TVRecEvent threadedfilewriter.cpp:129 (Open) TFW(/home/mythtv/live_tv/1057_20200108191
                                                                          eno: Permission denied (13)
Jan 08 19:16:46 origen.asandco mythbackend[7209]: mythbackend[7209]: E TVRecEvent tv_rec.cpp:4612 (GetProgramRingBufferForLiveTV) TVRec[1]: RingBuffer '/home
Jan 08 19:16:46 origen.asandco mythbackend[7209]: mythbackend[7209]: E TVRecEvent tv_rec.cpp:4648 (CreateLiveTVRingBuffer) TVRec[1]: CreateLiveTVRingBuffer(5
Jan 08 19:16:46 origen.asandco mythbackend[7209]: mythbackend[7209]: E TVRecEvent tv_rec.cpp:3782 (TuningFrequency) TVRec[1]: Failed to create RingBuffer 1

The first line talks about 'permission denied' but this is the result of # ls -al

drwxrwxr-x 2 thelma thelma 4096 Jan 8 17:56 live_tv
the other files within that directory are all like this:

-rw-rw-r-- 1 thelma thelma 0 Jan 8 17:53 1024_20200106151922.ts

Terminating the frontend and again running /bin/systemctl status mythtv-backend.service it changes to this:

Code: Select all

Jan 08 19:33:43 origen.asandco mythbackend[7209]: mythbackend[7209]: I TVRecEvent tv_rec.cpp:3665 (TuningFrequency) TVRec[1]: TuningFrequency
Jan 08 19:35:09 origen.asandco mythbackend[7209]: mythbackend[7209]: I Scheduler scheduler.cpp:2356 (HandleReschedule) Reschedule requested for MATCH 0 1 0 2
Jan 08 19:35:09 origen.asandco mythbackend[7209]: mythbackend[7209]: I Scheduler scheduler.cpp:2469 (HandleReschedule) Scheduled 45 items in 0.0 = 0.01 match
Jan 08 19:35:09 origen.asandco mythbackend[7209]: mythbackend[7209]: I TVRecEvent tv_rec.cpp:3665 (TuningFrequency) TVRec[2]: TuningFrequency
Jan 08 19:38:44 origen.asandco mythbackend[7209]: mythbackend[7209]: I Scheduler scheduler.cpp:2356 (HandleReschedule) Reschedule requested for MATCH 0 1 0 2
Jan 08 19:38:44 origen.asandco mythbackend[7209]: mythbackend[7209]: I Scheduler scheduler.cpp:2469 (HandleReschedule) Scheduled 45 items in 0.0 = 0.01 match
Jan 08 19:38:44 origen.asandco mythbackend[7209]: mythbackend[7209]: I TVRecEvent tv_rec.cpp:3665 (TuningFrequency) TVRec[1]: TuningFrequency
Jan 08 19:38:56 origen.asandco mythbackend[7209]: mythbackend[7209]: I MythSocketThread(112) backendcontext.cpp:102 (SetFrontendDisconnected) BackendContext:
Jan 08 19:38:56 origen.asandco mythbackend[7209]: mythbackend[7209]: I MythSocketThread(112) mainserver.cpp:7674 (connectionClosed) Playback sock(55de60db8a9
Jan 08 19:38:56 origen.asandco mythbackend[7209]: mythbackend[7209]: I MythSocketThread(117) mainserver.cpp:7674 (connectionClosed) Monitor sock(55de60db94d0

I am baffled, a not infrequent occurrence.

[bill6502]

I'd verify that all directories in the path have read/write/search permission, not just live_tv.
Note that the backend typically runs as user mythtv and the above is owner/group thelma.

systemctl status --no-pager mythtv-backend.service will get proper logs, without --no-pager,
you get the truncated lines above.

Please put logs in code display, you highlight the text and then click on the: less than,
slash, greater than icon.

[pinnerite]

You were spot on.
Thank you.

I reckon I blindly changed the user:group of /home without considering all the consequences.

I've made notes to remind me.