Double tuners finally working

There are a lot of blind roads I got led down trying to figure this one out. To recap: Master backend in living room, slave backend in bedroom, PVR-150 in each. MBE refuses to see tuner in SBE, SBE refuses to see tuner in SBE.

Part of problem is related to both boxes defining tuner card as /dev/video0 which confuses MBE's database (not sure why). Googling 'force /dev/video1' was a mistake because the solutions to that had to do with boxes with multiple tuners, not ecologies with multiple tuners in separate boxes, and udev rules won't really fix my problem because they're more useful to fixing which device inside a box gets enumerated first.

No, what I needed was to tell the MBE that it was /dev/video1 and let the SBE stay /dev/video0. This isn't done with /etc/udev/rules.d/ rules files, this is done in /etc/modprobe/aliases with a simple line:

options ivtv ivtv_first_minor=1

Much, much easier than futzing with udev. The next step is to follow these instructions: Delete all the tuners on both boxes, set up the tuner on the SBE first (Mythbuntu deliberately doesn't have a menu option for mythtv-setup, so you'll have to run it from a terminal), then set up the tuner on the MBE. Nota Bene: you will not see the SBE tuner in the list of tuners as you create the MBE tuner. Do not freak.

Now, I have two machines which can simultaneously show separate live TV feeds, and the MBE automatically reshuffled the recording schedule to permit simultaneous recordings on both boxes. Amusingly the two tuners are known as 2 and 3 globally and each is Tuner 1 locally.

The remaining PITA at this point has to do with the audio on the new MBE: neither the VIA 82xx chipset nor the ancient Creative card I put in it allow Myth to control the volume, despite GNOME being able to do so. But the dual tuner situation has been a major victory.