[mythtv] Ticket #10414: HDHomeRun: Bad Recordings (was: Bad Recordings - Choppy Playback)

[Tom Lichti]

On Fri, Mar 9, 2012 at 12:44 PM, Derek Atkins <warlord at mit.edu> wrote:
> Tom Lichti <tom at redpepperracing.com> writes:
>
>>>>  Does this happen with the latest HDHomeRun firmware? I assume some if it
>>>>  happens with the prime as well; but I want to be sure you are using RTP
>>>>  and not UDP streaming.
>>>>
>>>
>>> Yes,  I have the latest firmware.   I downloaded and installed it about a
>>> week ago as a trouble shooting step. I'm not sure how to verify it was rtp
>>> and not udp.
>>>
>>> I'm almost certain it was both the prime and HDhr devices, but I cannot
>>> recall with one hundred percent accuracy right now.
>>
>> Unfortunately even with the change put in today by Daniel, I still see
>> the problem. The 4 concurrent HDHR streams are too much. CPU is still
>> around 75-80%, and all recordings in progress become choppy. It is
>> definitely the recordings, if I play them back after they are still
>> choppy.
>
> This leads me to believe the issue is that your backend cannot keep up
> with all the data streams.  Perhaps the disk is too slow, or there's a
> problem with the network card, or interrupts?  Can you run 'top' and
> see, for example, if e.g. there is ksoftirqd spinning while all these
> recordings are running?
>
> I'm seeing similar things here, but I don't think it's a mythtv issue or
> an HD Homerun issue.  I think it's a hardware issue on my backend
> server.

I'm trying to rule that out. I don't think it's network or interrupts,
I have all Gig-E networking, and the backend is actually a server,
Dell Poweredge SC1435, so the only thing I can see is it being the
disk. I'll try putting a storage group on another disk and test that
and report back.

Tom