I'd still personally build ext3 into the kernel (ie non-modular), simply because it's always going to be in use. Modules have some overhead.

I think I'll stick to the RedHat supplied kernel. This box is my mail DNS/MX server, the overwhelming requirement is that it be stable and reliable. Memory usage and performance come second.

wrt to your UPS situation, if you have an APC UPS then check out apcupsd. apcupsd will run in network mode, so one UPS can trigger multiple machines. Runs fine on *nix and Win.

I'll have to take a look at that. Not before I got on holiday though, it looks complex enough to screw up so that it doesn't work on the first attempt...