MythTV with Retro Theme     So many PVR problems, so little time.


     There was once a time when I was very happy with my PVR. It had a couple of minor bugs but the only thing that it really needed from me was to clean out the hard drives every once in a while so that it didn’t run out of space.


     Now we have a master back end with 1.4TB of storage and a secondary back end next door and things are running like crap. The master back end crashes constantly, the secondary crashes constantly. Until recently the master back end’s PVR-150 had an awful tinny audio issue. Currently I’m having a random no audio issue on the secondary back end. There’s a problem where in the first 7(ish) seconds of video it stops and jitters and then you miss another 15(ish) seconds of video in the recording.


     So, we need a strategy. I’ve been reading a whole lot trying to find out where to go to get this stuff working because I’ve invested far too much time to go back now. Basically it seems that there’s one or two problems.

  • The first is that the memory errors which are being logged to the console and sometimes result in the mythbackend process crashing could actually be because the video can’t be written to the disk fast enough. I’ve seen this problem a few times on the secondary back end, and I know that system’s system drive is making awful sounds, so I’m guessing that rebuilding that onto the bigger drive may just do the trick.
  • Because the master back end is using Logical Volume Management to make all of those drives show up as one drive, there’s a performance decrease there, so for the purposes of testing, put in a different drive to run as the storage drive to see if that has any effect.
  • Then network-wise I’m not having any significant issues, but I’m wondering if putting all of the systems in one network with a reliable switch would help. Right now the front end at my house is on a different network than the back end at Sean’s which works, but I’m wondering if the master back end is doing needless switching because of that, which should drop performance, but technically could.
  • Another possibility is that the master back end system actually does need more than 512MB of RAM. Perhaps that’s because the LVM uses ram to make things happen so when it needs that RAM to write the recording TV buffer, there just isn’t enough of it 7 seconds into a video? If running with just one disk solves that problem, then that could have been the problem too.

     The system really needs to get to a more stable point because I would really like to add a third back end, so that when two recordings are going simultaneously, we could watch that other live feed, or better yet have all of the programming that we want to watch for the night recorded by 10pm instead of re-arranging things so that it’s all done by 4am and you have to watch it the next day.


     I’m going to figure out a plan today and execute it tomorrow.

Author: Ian

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