[mythtv-users] Commercial flagging on backend disrupts HDTV playback on front end

[Joshua M. Thompson]

On 9/10/07, Taco Mel <taco_mel at yahoo.com> wrote:
> With my current settings I have experienced a problem
> with playing back HDTV (prebuffer pauses, very
> jittery) when the back end server is "busy":
>
> 1. Recording HDTV stream with pcHDTV 5500
> 2. Recording SDTV stream with Hauppauge 500
> 3. Commercial flagging #1 and #2
> 4. Feeding HDTV stream #1 to remote front end
>
> The back end has 1 TB storage in RAID-5 and is a dual
> Xeon 1.8 GHz setup, hyperthreading enabled.  Linux
> sees this as 4 CPU's.  There I find a "mythcommflag"
> process using 100% of a CPU (iowait around 5-20%).
> The front end (Athlon X2 5200+) isn't even breaking a
> sweat. I tried to "renice" the mythcommflag process to
> +19 on the back end and this did not help.  Killing
> mythcommflag on the back end immediately "fixed" the
> problem.

What about MySQL? Is it stored on the RAID or do you have a separate
OS drive? You might be hitting a bottleneck trying to handle all those
SQL transactions at once.