[mythtv-users] Fixed: Choppy watching current recording.

Billy Macdonald billymacdonald at gmail.com
Thu Jan 25 22:44:08 UTC 2007


Hi,

    I just setup two HD Homerun devices and was having problems
watchingrecording in progress.  I was getting prebuffering pauses and
top was showing 15-25% iowait.

   I could record four HD shows at once and watch a fifth prerecorded
HD show and that was fine, it was only watching a recording in
progress that was bad.  I changed the NFS mount options from a rsize &
wsize of 32768 to a rsize & wsize of 8192.  This lowered the iowait
times to around 4%.  Playback of a recording in progress now works.

   I'm not quite sure why this made the difference as I have the
network bandwidth since watching a HD recording while four others are
being recorded shows an iowait of 0% and no problems at all.
Myth-0.20-fixes.  Maybe the it was the file access in 32k chunks that
was the problem?

My frontend and my two hdhomeruns connect to a 1G switch to another 1G
switch to the backend as attempted to diagram below.

Frontend -- 1G --
HDhomerun --100 -- Dlink -- 1G -- Dlink -- 1G -- Backend
HDhomerun -- 100 --

I couldn't find much info troubleshooting this but after the fix I
noticed that 8192 is the suggested value in the setup docs, so I guess
it's there for a reason.

Billy


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