[mythtv-users] Charlie Rose via PVR-350

[Mark Knecht]

On 9/20/05, Mercury Morris <mercury.morris at gmail.com> wrote:
> On 9/19/05, Michael T. Dean <mtdean at thirdcontact.com> wrote:
> > Could this be a problem with your system (instead of a problem with
> > Myth) that others are seeing where running mythfilldatabase (or wget of
> > any kind) while recording causes an IOBOUND situation that prevents
> > information from being written properly and causes an A/V sync offset? 
> > In other words, does Charlie Rose happen to record around the time your
> > mythfilldatabase runs?
> > 
> >
> http://www.gossamer-threads.com/lists/mythtv/commits/150176
> 
>  Yes Mike !  In the mythbackend.log, there are IOBOUND entries that
>  correspond in time exactly! to the discontinuities in the Charlie Rose
> show.
>  
>  But here's the thing:  I had already suspected mythfilldatabase because
>  it had been running within the Charlie Rose hour. So, I changed the 
>  window for mythfilldatabase to run outside of that hour - problem still
>  occurred.

Did you completely restart the backend mysql processes after doing
this? Maybe even reboot to be sure?
>  
>  So, mythfilldatabase is not the cause, BUT the system is recording
>  Letterman (in HDTV) from an HD3000 card at the same time.  
>  I guess that the simultaneous recordings are too much for the I/O
>  system to handle - a bit of a surprise to me.

Not likely unless you have no DMA on your hard drives or the data is
traversing the network. My backend storage is not on my backend
server. I never see problems like this but I don't record HD either.
None the less that should be less than 5MB/S which even a non-DMA hard
drive might keep up with...


>  
>  But now, thanks to you pointing me to the logs, I can set up the
>  recording schedules so that only one recording takes place at a time.
>  (Of course, I feel that I should have looked in the logs without having
>  to be told to.)
>  
>  One more observation, about a specific time:  Last night's out-of-sync
>  break occurred at 36:19 into the Charlie Rose show.  That's within the
>  first two minutes of Letterman.  Maybe there is extra overhead at the start
>  of a recording?

Possibly.

Cheers,
Mark