CompTIA A+® Certification All-In-One For Dummies®, 2nd Edition

5.8. Securing Data with RAID

Windows servers have a built-in software implementation of RAID (Redundant Array of Inexpensive Disks) that you can take advantage of. RAID is a method of implementing redundancy — duplicated information — on your hard drives. If one disk fails, the other disk(s) can provide the missing information. RAID is a method to implement fault tolerance: the idea that in case of a hardware failure in the system (say, a hard drive fails), the system can continue to operate as normal. There are many different levels of RAID, but the only RAID levels that provide redundancy in Windows Servers are RAID 1 and RAID 5.

NOTE

Windows servers also support RAID 0, called disk striping or striped volumes. No redundant information is stored on striped volumes, which is why striped volumes are classified as RAID 0. (Think of it as a zero level of redundancy.)

5.8.1. Mirroring/duplexing (RAID 1)

The type of hard drives typically found in servers are SCSI drives, which means that a SCSI adapter (controller) connects the drives to the systems. Disk mirroring is the use of two disks on a single controller to create full redundancy — whatever is placed on one disk is copied to the second disk. When creating a disk mirror, you must use two disks so that if one disk fails, you can rely on the copy of the data stored on the other disk.

When the mirror is established, you have a new drive letter accessible from the My Computer (Computer; Vista) icon. This drive actually shows the ...