Well, Raid is the way of the future, and the way of now. I haven't seen a server in a long time that didn't have a raid array setup. Especially with raid 5. There aren't as many that use SATA as do SCSI, but still RAIDed.
For basic setup and for extra storage space, I go with RAID 0, because it is striped(which means that data is shared on both drives), which doubles HD storage, but it is also not very fault tolerant. If one hard drive goes bad, the array is finished and the data on the other hd is no good. Whereas, RAID 5 combines striping and mirroring(if i'm correct). For example, if you have 4 80GB hd's in raid 5. Your total storage space is 240GB with 80 being reserved for data checking. In succession, the hd's are used to check eachother, thus eliminating unnessecary spin. In a raid array, you can dramatically lessen the lifespan of your drive. that was part of the problem with some other of the raid arrays. Lets say I have 3 drives. A, B, and C. I Install a windows hotfix on A: C is then updated as well, Now I install a hotfix on B: C is once again accessed. You will burn up that third drive twice as fast as the other ones.
