Parity set optimization for RAID 6 protection

RAID 6 IOAs provide optimal performance, capacity, and balance, so selecting any of the parity set optimizations, other than Availability, will not affect the outcome of the parity sets.

When you select to optimize a parity set, the IOA will choose disk units for parity sets according to the optimization value you have chosen.

When not in a dual storage IOA configuration, RAID 6 IOAs provide optimal performance, capacity, and balance, so selecting any of the parity set optimizations, other than Availability, will not affect the outcome of the parity sets.

When in a dual storage IOA configuration, using Performance parity set optimization is recommended to provide optimal performance, capacity, balance, and availability.

Availability

A parity set optimized for availability offers a greater level of protection because it allows a parity set to remain functional in the event of a I/O bus failure. The parity set is formed from at least four disk units of equal capacity, with no more than two disk units attached to an individual bus on the IOA.

Performance

When in a dual storage IOA configuration, the system attempts to create an even number of parity sets. An even number of parity sets distributes the workload evenly between a pair of adapters which are in a dual storage IOA configuration. This provides the fastest data access since each adapter has a piece of the workload.