Device parity protection

 

Device parity protection uses a data redundancy technique that protects data by spreading the parity data across multiple disk units in the parity set. When a failure occurs on a disk unit that has device parity protection, the data is reconstructed.

To protect data, the disk IOA calculates and saves a parity value for each bit of data. Conceptually, the IOA computes the parity value from the data at the same location on each of the other disk units in the device parity set. When a disk failure occurs, the data can be reconstructed by using the parity value and the values of the bits in the same locations on the other disks. The system continues to run while the data is being reconstructed. The overall goal of device parity protection is to provide high availability and to protect data as inexpensively as possible.

Device parity protection is not a substitute for a backup and recovery strategy. It is necessary to perform routine saves of your system.

• Device parity protection concepts
  Learn more about RAID 5 and RAID 6 protection to decide which level of protection is best for you.

• Starting device parity protection
  The best time to start device parity protection is when you add new or non-configured disk units. The Add a disk unit or disk pool wizard has steps for including disk units in a parity set and starting device parity protection.

• Managing device parity protection
  Refer to this topic to see the tasks that you can perform to manage your disk protection activities.

• Device parity protection examples
  Refer to this topic to see examples of device parity protection works when a disk failure occurs.

• Using hot spare device parity protection
  Protect your disk units with hot spare device parity protection.

 

Parent topic:

Disk protection types

Related concepts
Managing geographic mirroring