Microsoft® SQL Server 2012 Unleashed

RAID Level 5

RAID 5 is most commonly known as striping with parity. In this configuration, data is striped across multiple disks in large blocks. At the same time, parity bits are written across all the disks for a given block. Information is always stored in such a way that any one disk can be lost without any information in the array being lost. In the event of a disk failure, the system can still continue to run (at a reduced performance level) without downtime by using the parity information to reconstruct the data lost on the missing drive.

Some arrays provide “hot-standby” disks. The RAID controller uses the standby disk to rebuild a failed drive automatically, using the parity information stored on all the other drives in the array. During ...