RAID Volumes

The acronym RAID refers to Redundant Array of Independent (or Inexpensive) Disks-it is a series of separate disks configured to work together as a single drive with a single drive letter. You have already seen three of the most common types of RAID arrays in Table 15-2: RAID-0 (disk striping), RAID-1 (mirroring), and RAID-5 (disk striping with parity). Other versions of RAID also exist but are generally unused.

When you use fault-tolerant volumes, a disk can fail and the operating system will continue to function. The failure can be repaired with no loss of data. Most Windows 7 computers do not have fault-tolerant volumes. An administrator should understand how to handle the errors that can plague a hard disk. Refer to previous section Table for common problems that can also plague fault-tolerant volumes.

CAUTION: Don't confuse the RAID-5 or mirrored volumes that you can create within the Windows 7 operating system with RAID-5 or mirrored drives that are configured in a hardware storage array. A disk array produces a highly performing, fault-tolerant volume that appears in Windows 7 Disk Management as a simple volume. When you create mirrored or RAID-5 volumes in Windows 7, you achieve fault tolerance but lose some performance to disk management processes, especially if a disk fails.