CISSP All Domains Practice test 9

RAID (Redundant Array of Independent/Inexpensive Disks): Comes in 2 basic forms, disk mirroring and disk striping. Disk mirroring: Writing the same data across multiple hard disks, this is slower, the RAID controller has to write all data twice. Uses at least 2 times as many disks for the same data storage, needs at least 2 disks. Disk striping: Writing the data simultaneously across multiple disks providing higher write speed. Uses at least 2 disks, and in itself does not provide redundancy. We use parity with striping for the redundancy, often by XOR, if we use parity for redundancy we need at least 3 disks.