raid question

[Massive Attack]

hi guys, going to be setting up a raid 0 array with 2 x 320gb seagate 7200.10s and i was just wondering if i can set the volume to say 100gb and then have the rest on each drive non raid for storage if u see what i mean

 

[Massive Attack]

ahh ok guys, was going to put the OS on a 100gb partition and other data which i dont want to loose on the rest if i raid it all i could loose all the data, im not bothered about loosing the os as i can just re format thanks anyway