Home | Contents | Help   Raidhelp     Defining RAID Level 5 - Disk Striping with Distributed Parity By distributing the redundant information across all of the array's member disks, as contrasted to RAID Level 4's dedicated approach, RAID Level 5 alleviates the write bottleneck intrinsic to RAID Level 4. However, it is not entirely eliminated, resulting in asymmetrical performance - better read than write performance. Because of this intrinsic asymmetry, RAID Level 5 is often augmented with related storage technologies such as caching. Higher levels of reliability and availability are also achieved by distributing the redundant information rather than dedicating disk drives to the redundant information. RAID 5 offers the highest Read data transaction rate of all levels combined with a medium Write rate. The low ratio of ECC Parity disks to data disks offers hardware efficiency. Click here for an example of a RAID 5 configuration. Disk failure does have a medium impact on the total transfer rate and also incorporates the most complex controller design. Other RAID5 configurations may be: RAID5: An array of three or more drives with parity striped across all three member disks RAID 5+1: Two mirrored RAID 5 arrays RAID 5+5: Three independent RAID 5 arrays, each with a minimum of three disks, are configured again to a higher level RAID 5 array. This permits one of the arrays to fail completely without affecting the data integrity. Next: Level 6 Related topics: Defining RAID Levels EDAP Definition Understanding Parity     Raidhelp   RAIDhelp© Copyright 1999-2004 Antony Kershaw