About RAID Levels
RAID Utility lets you set up RAID sets based on the following RAID levels:
 Enhanced JBOD
 RAID 0 (striping)
 RAID 1 (mirroring)
 RAID 0+1 (mirroring a striped pair)
 RAID 5 (striping with distributed parity)
RAID Utility - About RAID Levels