[mythtv-users] pixelation when using nfs for playback

[Daniel Kristjansson]

On Mon, 2011-04-25 at 21:42 -0400, f-myth-users at media.mit.edu wrote:
> > Date: Mon, 25 Apr 2011 21:22:57 -0400
>     > From: Steven Adeff <adeffs.mythtv at gmail.com>
> 
>     > running Ubuntu 10.04.2 LTS, if I have my recording drives mounted by
>     > nfs I get pixelation on playback, especially of things currently
>     > recording.
>     > mythbackend:/media/myth/6/	/media/myth/6	nfs	user,bg,rw,rsize=32768,wsize=32768,tcp,intr,nfsvers=3,actimeo=0,async,nobootwait
> 
>     > is one of my mount options possibly causing this?
> 
> I'm suspicious of that actimeo=0; it can cause massive slowdowns in
> one of the four cases of which is client vs server vs whether you're
> pushing or pulling.  (I can forward details if anyone cares.)
> 
> Try actimeo=1 instead.  You'll be within 1 second of up-to-date,
> without the problems.  No idea if that's actually your problem
> here, but worth trying.

Can you post the details for the massive slowdown? An actimeo=1 adds
one second to the channel change time worst case, 500 ms average case,
as opposed to the the defaults which break LiveTV since we will
timeout before ever seeing data, and as opposed to actimeo=0 which
adds no time to the channel change time. I'm curious as to when
actimeo=1 might be preferred.

-- Daniel