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

Michael Rice mikerice1969 at gmail.com
Wed Apr 7 21:44:44 UTC 2010


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?


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