While a convention could be useful, it generally should not be needed. I'm flipping through the upgrade scripts, and it looks like fstab is recreated during an upgrade instead of copied from the backup - generally a good thing.
Even with a convention for mount points, the device names would be different for everyone (does /myth/tv1 point to /dev/hda1? or /dev/hda2? or /dev/sda6?). A simplistic upgrade path would resemble something like this:
- - Query mythconverg.storagegroups for storage group locations
- Parse /etc/fstab from the backup and guess which additional entries need to be restored
There would be a fair amount of guessing required, but it could work.
A simpler method would be to set a line of demarcation in /etc/fstab: everything before the line is ignored; everything after the line is appended to the current /etc/fstab.
OR, you could choose not to monkey with the default "auto-mounts" provided by the install scripts (e.g. /dev/sda2 is mounted to /mnt/sda2), and then this becomes a non-issue, eh? /dev/sda2 ALWAYS will mount to /mnt/sda2, and your storage group information will copy over during the upgrade, so all should be good.
Just thinking out loud here.
I'm liking that last option, myself.