After the usual amount of sys admin fiddling, I've moved most of my Drupal sites onto a new server: an Apple 1.66 GHz Core Duo Mac Mini. Over the coming weeks I'll be doing some performance tuning and testing to see how it stacks up against the old server, a Dell SC 1425 dual Xeon box.
I wiped the Mac Mini's drive and installed Ubuntu 9.04 server, which took a bit of fussing, but turned out to be pretty easy once I figured it out (more details on that later; basically I had to install 8.04 and do an online upgrade to the newest version)
The box is sitting beside me - tiny, silent, consuming only 23W or so at idle, 110 at full CPU, compared to almost four hundred watts for the old server. Actually, I suspect that these figures are a bit on the high side. I'm planning to actually measure the power consumption, but that's a project for another day. I suspect that the humble Mac Mini has one of the best performance ratings per Watt consumed of any server anywhere. The new (2009) ones are even leaner. I have to say that I'm in awe of this little box.
It's running 'headless' (needs no monitor or keyboard to boot up) thanks to a bit of hardware hackery that I found here. I took photos and documented the (pretty quick and easy to do) assembly of the dongle in this flickr photoset.
Next steps: install a faster, more robust drive (perhaps an SSD?) and get SELinux working. Also web performance benchmarking.