Installing Ubuntu on my DL380 G2 was pretty straight-forward but I did have a problem with the fans running at full speed. That high pitched squeal could be heard from our bedroom upstairs at the other end of the house. I had some real trouble finding a solution for this. It was clear that I needed the HPASM management tools but HP's sight only shows RedHat and Suse installs. I finally came across this: http://jaxbeachtech.com/node/80
There are links there to some drivers that I think HP considers "beta". You have to sign up to download them which is pretty silly. Oh well, it worked after I also had to manually download and install this lib from the Debian site.
All's quiet now. Yes! Now on to installing ZoneMinder.