[mythtv-users] Dual PVR250s + NFS = dropped frames

[David]

-----Original Message-----

>From: mythtv-users-bounces at mythtv.org
>[mailto:mythtv-users-bounces at mythtv.org] On Behalf Of Matt Perry
>Sent: Tuesday, July 27, 2004 7:34 PM
>To: mythtv-users at mythtv.org
>Subject: [mythtv-users] Dual PVR250s + NFS = dropped frames
>
>Hi,
>
>I currently have 2 PVR-250s in my backend (P3 1GHz, 320MB ram, 27GB disk)
>and access all my Myth stuff via NFS mounts.
>  
>
it's been said before that 256Mb is a bare minimum for a single card 
backend - look here first

>I increased the NFS block size to 64k, but when I try to record two shows
>at once, I still get a pretty significant amount of dropped frames.
>  
>
I'd drop the block size to 32k (you don't have much RAM)
what is your server doing?
if you max out your server whilst recording then you have problems.
I suffer from this 'cos my server has raid5 and if I copy nuvs to and 
from other workstations then it tops out on the raid5 daemon and the 
nfsds (athlon 1200 server)

There's no way of specifying to nfs that a particular client has a 
higher priority :(
I have wondered about nfs over tcp...

># cat /etc/fstab | grep mythtv
>stratosphere.internal.unshift.net:/var/local/mythtv /var/local/mythtv nfs
>rsize=65536,wsize=65536,soft,nfsvers=3 0 0
>
>I really can't figure out how to solve this problem, except for some sort
>of rip/rsync type of hack.
>  
>
no need

>I'm also looking into channel bonding on both machines, to effectively get
>200Mbit worth of bandwidth.  I'd consider moving to Gigabit, except that
>requires all sorts of new and expensive equipment...
>  
>
it's not a network bandwidth problem (or, more correctly, 100mbit is 
plenty!)
my frontend can record to nfs(1), read a stream from nfs(2) for local 
playback, read another stream from nfs(3) and send it out(4) to a remote 
frontend and not break a sweat.
(I am going to gigabit - but for the server and workstations, not the 
myth stuff - if you don't believe me

>Anyhow, just wondering if anyone's run into this problem, or even if
>someone who hasn't cares to chime in.
>  
>
Install something like gkrellm and see what is going on.
I suspect your CPU or memory is maxing out (from nfs, not encoding)

David