[mythtv-users] glitches in HDHR recordings every 5-6 seconds

[Mike Perkins]

Michael Rice wrote:
> Currently using:
> 
> MythTV Version   : 23548M
> MythTV Branch    : branches/release-0-22-fixes
> Network Protocol : 50
> Library API      : 0.22.20091023-1
> QT Version       : 4.5.3
> 
> There seems to be some kind of evil IO going on every few seconds that
> is causing this.
> 
> I did an experiment and started one HDHR recording.  I see that top
> reports a load of
> about 0.12.  No problem.  Looking at iotop I see that mythbackend is
> steadily writing
> 1700K/s to 2000K/s.
> 
> Next I start another HDHR recording on the second tuner.  Now load
> increases quickly
> until it is in the 3.00-3.50 range.  Looking at iotop now shows a
> little higher 2000K/s to
> 2400 K/s.  But it also show huge spikes every few seconds such at
> 19,000K/s to 20,000 K/s.
> 
> It looks like the first recording is being written steadily but the
> second is being buffered and
> written in one big burst every 5-6 seconds.  Does anyone know what
> might be causing this?
> I've had this HDHR for a long time and this seems to only have popped
> up within the last
> several months.
> 
> Anyone have any ideas?
> 
Possibly it's flushing the (buffered) seek information to the database.

-- 

Mike Perkins