My "VPN Matrix" desktop computer has the Fastrak controller. I was able to use it at first in Linux, if I booted up with a non-raid drive, but Promise doesn't release reasonably recent drivers. I found the partial source code once, but with newer kernel versions ( >2.4.2) it won't compile. A couple months ago I read that they were going to release drivers for 2.6 kernels, but this wasn't the case.
I ended up buying an ATA-133 IDE controller and installed Linux Raid.