Help with recommended RAID configuration

[PistolPete30]

I've recently moved our web servers to a fully managed solution and have been left with a couple of spare servers. I'm going to use one to run Exchange 5.5. The data will be stored on a Sun STOREDGE A1000. However, the server itself has an Adaptec 2100S SCSI RAID system and I would like suggestions on how to configure it. If I have the 4 disks in a RAID 5 configuration it seems a waste of over 50Gb just to have an operating system and Exchange sitting on it. I've thought of maybe removing 2 disks and then mirroring the other two. Any suggestions?

 

[jimbopalmer]

Pete sometimes you're need for speed exceeds your need for capacity, if you do a RAID 10 (mirrored stipes) it squanders 50% of capacity but maximizes speed and reliablity. I tried to remain child-like, all I acheived was childish.