First off follow the below howto to format and mount the drive.
http://forums.ev1servers.net/showthread.ph...mount+2nd+drive
Then the below to backup files to it
http://samba.anu.edu.au/rsync/examples.html
I did the first step and it works flawlessly- just make no typos!! heh
I am personally when time allows gonna start the stage two which is rsyncing the files to the backup drive.
Hope that helps- I have the exact same machine plus a few others :-D
BTW i would sugest to run the distributed.net client on it to burn out tegh machine before making it a production server (its just force of habit for me- to test everythign to death)