[mythtv-users] nfs pauses

[Yianni Vidalis]

----------------------------------------
> From: yiannividalis at hotmail.com
> To: mythtv-users at mythtv.org
> Date: Mon, 16 Nov 2009 18:16:16 +0200
> Subject: Re: [mythtv-users] nfs pauses
>
>
>
>
> ________________________________
>> Date: Fri, 13 Nov 2009 17:20:03 -0800
>> To: mythtv-users at mythtv.org
>> From: mache at creeger.com
>> Subject: Re: [mythtv-users] nfs pauses
>>
>>
>>
>> What do you have under "General Playback
>> (1/9)?
>>
>>
>> I have the following items checked.
>>
>>
>> Extra Audio Buffering
>>
>> Clear saved position on playback
>>
>> Alternate clear saved position
>>
>> Jump to Program OSD
>>
>> Always stream recordings from the backend
>>
>> Enable picture controls
>>
>>
>> The checking of "Use video as a timebase", may cause this type
>> of problem.
>>
>>
>> -- Mache
>>
>>
>> At 11:35 AM 11/13/2009, David Brodbeck wrote:
>>
>> On Fri, November 13, 2009 11:22
>> am, Yianni Vidalis wrote:
>>
>>> There was no extra cpu activity during the pauses. Also, the
>> network
>>
>>> activity was flat when no pause was occuring (nothing else was
>> moving from
>>
>>> or to the nfs server). The pauses occur when mythtv fetches the next
>> piece
>>
>>> of the video (or when the nfs client does). You can see my
>> description on
>>
>>> my first post, if you'd like.
>>
>>
>> OK, figured it was worth a shot.
>>
>>
>> Last time I had a problem like that it turned out to be a flaky
>> network
>>
>> card. Under heavy load it would drop a few packets, then NFS would
>> sit
>>
>> around waiting for RPC retries.
>
> Sorry for the big delay, but I was busy trying out things. The only setting I hadn't selected was "Always stream recordings from the backend". Turning it on didn't change anything.
>
> I also tried cifs mount instead of nfs. Still pauses.
>
> The nfs server (again) is now opensuse 11.2, 2.6.31.5 kernel. Still pauses. (By the way, trying it I ran into the "no keyboard + mouse" bug. It is solved by entering ' Option "AutoAddDevices" "Off" ' under Serverflags in xorg.conf. Google helps!)
>
> I was wrong about the extra cpu activity during the pauses, it is clearly spiking. The nfs server is idle the rest of the time.
>
> I even uninstalled the avg antivirus I had installed, just in case. No improvement. There are pauses, still.
>
> I changed my ext3 filesystem to ext4. Still pauses.
>
> My nfs server cpu is a Intel(R) Core(TM)2 Duo CPU E4500 @ 2.20GHz. It should be able to handle easily this kind of lvm/raid5 configuration. The network through-output is 10~12mb/s. It's just with mythtv video that I have these pauses.
>
> I have already ordered a Q9400 Quad Core cpu ( I have been looking for an excuse, anyway ), should be here it 3-4 days - the retailer is out of stock.
>
> If any developers are reading this, is there a remotely remote chance that myth is asking for the rest of the video when the buffer I assume it uses is too low, not allowing for any latency (network or filesystem?). If this is the case, is there a way to change this?
>
> I am really running out of ideas, but if I find the time (kids + wife allowing) I will revert myth to a>2 month backup and try again. That will be the last resort!
>
> Thanks for reading this.
>
> Yianni.
>
> _________________________________________________________________
> Νέα Windows 7: Απλοποιήστε τις καθημερινές σας εργασίες. Βρείτε τον κατάλληλο υπολογιστή για εσάς.
> http://windows.microsoft.com/shop
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

Well, just to finish the story:
 
Reverting to an old (24 September) myth svn backup cured nothing. Back to current version.
 
The Q9400 cpu didn't help much, either - mythwise, that is. The system is VERY fast now for everyday use.
 
I copied all my data to another hd, removed the logical volume and left only the raid 5 array. I then created an ext4 filesystem on that and copied the data back.
 
All is ok now, no latency, no pauses.
 
This will be a lesson for the future for me, "Unless you get REALLY FAST hds, (I guess velociraptors could do it, but I have 4 x WDCWD6400AAVS) DON'T put lvm on top of a raid 5 array". The latency is ok for everyday use, you won't even notice it, but trying to play H.264 5.1 video through the network (nfs or cifs) using myth, nooooo.
 
 
Yianni.
 

  		 	   		  
_________________________________________________________________
Νέα Windows 7: Απλοποιήστε τις καθημερινές σας εργασίες. Βρείτε τον κατάλληλο υπολογιστή για εσάς.
http://windows.microsoft.com/shop