Database Hardware

RAID stands for Redundant Array of Inexpensive (Independent) Disks.

RAID 0  = 2 or more disks, excellent performance, no copies.
RAID 1  = 2 or more disks, good performance, excellent copies.
RAID 5  = 3 or more disks, good performance, good copies, use for read oriented.
RAID 10 = 4 or more disks, excellent performance, excellent copies, best.

Consider using RAID 10 for main database, RAID 1 for transaction logs and RAID 1 for the boot disk.