[mythtv-users] RingBuf issues - perhaps

[Mark Garland]

Hi all,

I’m newish to mythtv, and very new to this mailing list, so feel free to
suggest basics.
I’ve recently built a combined frontend/backend machine, but have been
having a few issues.
My current problem is that the frontend will randomly lock for 3-5 minutes
mainly when watching live tv (recorded is usually fine) and will then take
me back to the screen showing the list of recordings.

A week ago, it locked at exactly the time when 2 other recordings were due
to start.  I suspected the harddisk was just temporarily very busy for a few
seconds while these recordings started, and that the buffer had run dry.  I
upped the Ring Buffer from 4mb to 50mb to cope with stressful situations and
this improved things.

However, last night, whilst changing channels, it locked.  The frontend logs
show...
2009-07-18 17:20:28.594 NVP: Prebuffer wait timed out 10 times.
2009-07-18 17:20:37.168 NVP: prebuffering pause
2009-07-18 17:20:38.770 NVP: Prebuffer wait timed out 10 times.
... repeated over 100 times, about once a second for the duration of the
lock ...
2009-07-18 17:25:07.775 NVP: Prebuffer wait timed out 10 times.
2009-07-18 17:25:36.518 RingBuf(/content/mythtv/1001_20090718172025.mpg)
Error: Waited 34 seconds for data, aborting.

Then, this morning when watching a program that was being recorded (a few
minutes behind live), it locked.  Frontend logs show...
2009-07-19 09:33:42.349 NVP: prebuffering pause
2009-07-19 09:33:43.196 RingBuf(/content/mythtv/1001_20090719085600.mpg):
Waited 2.0 seconds for data to become available...
2009-07-19 09:33:43.950 NVP: Prebuffer wait timed out 10 times.
2009-07-19 09:33:45.196 RingBuf(/content/mythtv/1001_20090719085600.mpg):
Waited 4.0 seconds for data to become available...
2009-07-19 09:33:45.551 NVP: Prebuffer wait timed out 10 times.
2009-07-19 09:33:47.152 NVP: Prebuffer wait timed out 10 times.
2009-07-19 09:33:48.753 NVP: Prebuffer wait timed out 10 times.
2009-07-19 09:33:49.198 RingBuf(/content/mythtv/1001_20090719085600.mpg):
Waited 8.0 seconds for data to become available...
2009-07-19 09:33:50.354 NVP: Prebuffer wait timed out 10 times.
2009-07-19 09:33:51.955 NVP: Prebuffer wait timed out 10 times.
2009-07-19 09:33:53.556 NVP: Prebuffer wait timed out 10 times.
2009-07-19 09:33:55.157 NVP: Prebuffer wait timed out 10 times.
2009-07-19 09:33:56.758 NVP: Prebuffer wait timed out 10 times.
2009-07-19 09:33:57.201 RingBuf(/content/mythtv/1001_20090719085600.mpg)
Error: Waited 16 seconds for data, aborting.
2009-07-19 09:34:07.833 TV: Attempting to change from WatchingRecording to
None
2009-07-19 09:38:35.193 TV: Changing from WatchingRecording to None
2009-07-19 09:38:35.733 DPMS Reactivated.

Can anyone suggest what I should do?  Should I put the RingBuffer at 100mb?
(there are warnings against making it too big).
Are there other areas that I can look at?  (To rule out the harddisk, I did
run iostat whilst myth was recording 3 programs at once and running
mythcommflag, and it rarely went over 30% usage).
Where else can I look?  Is there any other info I can supply?

Thanks in advance for any help received,

MG
-----
"The most overlooked advantage of owning a computer is that if they foul up
there's no law against whacking them around a bit."