I am about to setup my first frontend. I would like the output quality to be fairly decent and want to use KnoppMyth to install it. I am guessing it would easiest to install the whole release on the machine, but my question really is, do I get another PVR-350 for video to keep the quality high? Is there a cheaper solution that would still give results similar to the hardware out on the PVR-350?

The 350 output is supposed to be "best of breed", so almost anything else is going to be a step down. I've been pretty happy with an FX5200 based video card, but I'm not watching sports or the like where the deinterlacing artifacts are most noticable. I'm not aware of anything other than pvr-350 which preserves the interlacing. There are external devices which will do this from an MPEG-2 stream but they're more expensive.

BTW - If it's got a tuner card like a PVR-350 it's not really a frontend, it's a secondary backend...

If it is a secondary backend that is fine, I guess I will be adding yet another tuner to the pool but off of a another machine. If this is done, will both backends be able to play shows from each other? I know the mysql stuff will be held on the primary backend, but will it know where to bring up the shows from?

Recordings are shared across all the macines. I don't know if the local frontend even connects to the local backend or if it goes straight to the master.

Well, I tried this. I setup another machine as secondary backend by just installing KnoppMyth on it. I then selected the original backend as the master.

It shows my recordings, but when I try to play them I get a message that it can not find the show on /myth/tv.

So I guess you need to nfs mount the /myth directory between backends.

Yep, this worked. I simply nfs mounted /myth from the primary and now I can watch the recorded show. Had to start nfs-common and nfs-kernel-server but besides that it worked fine.

Actually thinking abou this, this may get a bit confusing when I add another card to the other machine. Then I think I would only share the /myth/tv directory and everything else would need to be local to each backend. Then I would need to schedule shows on each machine atomically. Although, once it is recorded it will be accessible by both.

This make sense?

No. you really want centralized scheduling, especially if you're sharing the same file storage. Think about what happens if you get two BEs recording the same program.

How would that be done? What needs to be shared exactly then? The mysql db is off of one server. But a tuner will be on another server. So how does it know which server to kick in the program on. Maybe I register them with different tuner numbers accross the servers.

Then If it is scheduled on tuner1, it goes to one machine, and if tuner2 then the other server?

You don't schedule the tuners that's what the software is for. You select programs that you want recorded and place restrictions on which, channel, what timeslot, how often, ... The MythTV scheduler then assigns the best available resources (tuners) to record the best available showing of that program. Go read the MythTV docs which have a very detailed section on how the scheduler works.

Having a master and secondary backends rather than completely independent ones allows this scheduling "intelligence" to pick the best resource across the whole distributed system.

Thanks tjc, this is exactly what I am coming to understand. RTFM for me

I have two tuners right now in one box. I will segregate the tuners into two boxes and one as tuner1 and the other as tuner2. The box with tuner1 will be the master and the other will be a secondary.