[oclug] Setting up MythTV

[Brad Barnett]

On Tue, 29 Mar 2005 16:56:28 -0500
Roger Messier <en916 at ncf.ca> wrote:

> To anyone that has a MythTV box, is it OK if MythTV is on a server box 
> with other stuff running (e.g. Apache, MySql, NFS, etc) if the hardware 
> is fast enough, or should it be on its own box no matter what the
> hardware?
> 

This is a difficult question to answer.  

I/O may be your biggest problem here.  Even with some of the, erm,
"better" I/O elevators in 2.6 (and, 2.6 on a server?!  No thanks!).  Myth
might skip on playback a bit, if you have a lot of disk contention.

Providing a dedicated ide hard drive, on a dedicated channel, would
probably be sufficient, even under I/O load.  With a PVR250, you won't be
using any noticeable CPU in terms of capturing, and a pause in I/O won't
hurt the capture process (with enough ram to buffer), so my statements
above primarily refer I/O for playback.

> I don't actually have the server box yet (it's a server that's being 
> decommissioned at work), so I can't give you the exact specs, but it's a
> 
> dual proc system (at least P3, maybe Xeon, not sure of the speed), at 
> least 1 GB of RAM, two SCSI disks (not sure of the size).  Given these 
> (very) approximate specs, do you think that it'll be enough if I use a 
> tuner card with hardware encoding like the PVR-250?

Dedicate one of those SCSI disks to I/O, and you'll be quite fine.  Are
you going to use the same box for playback of video, btw?  If so, you
*may* want to make MythTV realtime, but I shudder to think it. 
After all, a race in Myth would take that whole box down.  Not
preferable for a server.  However, playback is a very time dependant
thing.  Writing fields to video cards, or performing de-interlace
operations, as well as getting them to be displayed at just the right
time, does require constant CPU availability.