User guide

Understanding Drive Arrays D-5
Drive Array Benefits
Using drive arrays with the Smart Array 431 Controller has several important
benefits:
■ Data Protection
■ Performance Enhancement
■ Capacity Changes
■ Drive Movement
■ Data Reliability
Data Protection
The Smart Array 431 Controller provides several options to produce data
redundancy for a more reliable system including distributing data, fault
tolerance methods, assigning online spares, and rebuilding data automatically
to online spare drives.
Fault-tolerance (RAID) Options
During configuration, you will need to make RAID (Redundant Arrays of
Inexpensive Disks) level choice. RAID is a term used for an array technology
that provides data redundancy to increase system reliability and performance.
There are several RAID levels ranging from RAID 0 to RAID 5. The Smart
Array 431 Controller provides the following levels of RAID:
■ RAID 0 - no fault tolerance (data striping for performance only)
■ RAID 1 - drive mirroring (also RAID 0+1, also known as RAID 10)
■ RAID 5 - distributed data guarding
The fault tolerance method you choose affects the amount of available disk
storage capacity and the performance of your drive array. The following chart
lists the supported RAID levels and illustrates how the fault-tolerance method
you select affects performance and capacity.