Parity dataParity data is redundant data that is generated to provide fault tolerance within certain RAID levels. In the
event of a disk failure, the parity data can be used by the controller to regenerate user data. Parity data is
present for RAID 5, 6, 50, and 60.
The parity data is distributed across all the physical disks in the system. If a single physical disk fails, it can
be rebuilt from the parity and the data on the remaining physical disks. RAID level 5 combines distributed
parity with disk striping. Parity provides redundancy for one physical disk failure without duplicating the
contents of the entire physical disks.
RAID 6 combines dual distributed parity with disk striping. This level of parity allows for two disk failures
without duplicating the contents of entire physical disks.
Figure 23. Example of Distributed Parity (RAID 5)
NOTE: Parity is distributed across multiple physical disks in the disk group.
Figure 24. Example of Dual Distributed Parity (RAID 6)
NOTE: Parity is distributed across all disks in the array.
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