RAID provides a mechanism for fault tolerance and redundancy in file systems. Windows 2000 Server supports three RAID levels: 0, 1, and 5.

RAID 0 writes data across all volumes in the array to improve performance. RAID 0 volumes, also called striped volumes, allow the reading and writing of data to multiple disks in the array, which improves overall disk throughput.

However, RAID 0 volumes don't provide any redundancy. If a volume in the stripe set fails, the entire array is lost.

RAID 1 comprises two identical copies of a volume, each residing on a separate dynamic disk. This mirrored volume set provides redundancy in the event that one disk fails; the second disk in the set can continue to function until you replace the faulty disk and restore the mirror.

RAID 5 is a striped set with parity. It writes data across all volumes in the set (striped) as in a RAID 0 array, but it adds parity data to enable Windows to reconstruct the data if a disk fails.

A RAID 5 array requires at least three identical disks. The result is a performance improvement from striping and redundancy from the added parity data.

You can create each of these types of volumes on a Windows 2000 server using the Disk Management branch of the Computer Management console.

The RAID capabilities built into Windows 2000 can be useful for improving performance and adding redundancy in a variety of situations. If you require even better performance or additional RAID features, consider one of the many hardware-based RAID solutions available for the Windows platform.