RAID 4 is a Level that uses a Dedicated Parity Drive, and is a commonly used implementation of RAID. Level 4 provides block-level striping (like RAID 0) with a dedicated parity disk. If a data disk fails, the parity data is used to create a replacement disk. A disadvantage to Level 4, is that the parity disk can create disk write bottlenecks, severely cutting performance.
|RAID Number List|
|RAID 0 | RAID 1 | RAID 2 | RAID 3 | RAID 4 | RAID 5 | RAID 6 | RAID 0+1 | RAID 1+0 | RAID 7 | RAID S | JBOD|