RAID

RAID stands for “Redundant Array of Independent (formerly “Inexpensive”) Disks.” RAID is a collection of hard drives in a computer that is used for performance enhancement and/or fault tolerance. Windows server versions (Windows NT and 2000 Server, and Windows Server 2003) have built-in support for some levels of RAID, but hardware-based RAID systems provide better performance. The most basic level of RAID uses two hard drives to increase performance, while higher levels store data on two or more drives so that if one fails, the data won’t be lost. SCSI or SATA drives are usually used in RAID systems. In hardware-based RAID systems, it is common for the drives to be removable; they are kept in a caddy that is accessible through an opening in the case. When one fails, it can easily be replaced. More advanced systems employ hot-swappable drives. These are drives that can be removed and replaced without shutting down the system. Naturally, all this technology is much more expensive than standard PCs, so it is used mainly in business and government situations in which downtime and/or data loss would be catastrophic to the operation of the organization. For more information on RAID, see raidweb.com, and search the Web for more articles; there are many.

Tip

Early in the Windows 2000/XP installation process, you are prompted to press the F6 key in case you want to install drivers for a special drive controller. You must do this if you want to install the OS on a SCSI drive. If you are setting up hardware RAID with SCSI or SATA drives, or could be using RAID later, make sure you supply the RAID drivers at this point or you will probably have to reinstall the entire system when you do want to use RAID. The option to press <F6> is available for only a few seconds. Also, if there is such a setting, make sure RAID is enabled in the BIOS.