[mythtvnz] Pixelation/Corrupt recordings

[Aaron Pelly]

On 07/07/14 11:23, Steve Hodge wrote:
> On Mon, Jul 7, 2014 at 10:59 AM, Aaron Pelly 
> <apelly at monkeymasters.co.nz <mailto:apelly at monkeymasters.co.nz>> wrote:
>
>     Hardware:
>     - core2 duo ~3GHz
>     - 4G RAM
>     - many 7200rpm HDDs, but with only two configured as storage
>     groups. drives are currently ntfs. This will change in the next
>     few days.
>     - 2 HVR4000 tuners
>     - Cheapo Nvidia card, (gt9500?), doubt that's relevant.
>
>     I do have a motherboard with a core2 quad and 8G ram that I'll
>     probably stick in the backend this week. Maybe I should just try
>     that first?
>
>
> You've got more than enough CPU and RAM  for recording, I doubt this 
> will help unless there is something else running on the box?
I do use it as a PC too, so sometimes firefox is running. Firefox, for 
me, is like having a bloody gorilla in your RAM. I had thought (but not 
checked) that this would swap out when I wasn't around for a while. 
Frontends on other machines report 3.9GB total, 3.7GB used, 138MB 
available. This is pretty consistent no matter what the backend is up 
to, so I suspect a myth bug. gnome-system-monitor reports about 900MB 
used at the moment. At the moment I'm not having recording issues either...

>
>     - it might be worse when there are multiple simultaneous recordings
>     - it comes and goes
>     - might be worse when the backend has low ram
>     - seems a bit better after rebooting the backend
>     - not sure if it affects dvbs or just dvbt
>     - i haven't done the math for required throughput for the HDDs or
>     the PCI bus.
>
>
> If it's not consistently happening with simultaneous recordings it's 
> probably not a throughput issue. You could try recording say 6 things 
> at once to test this.
I will try this.

> Is there anything else hitting those drives?
Can't think of anything. I'm about to move a bunch of data around and 
get them formatted as ext4/xfs as appropriate. I will see how/if this 
affects recordings in progress.

> What about the drive with the database?
SSD

>
>     Of course, this might be simply bad reception. I haven't seen any
>     correlation with terrestrial weather. Have not looked at solar
>     weather.
>
>
> Bad reception would be my guess. Does it happen during live TV?
Yes.
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