Oracle Solaris ZFS Administration Guide

Double-Parity RAID-Z (raidz2)

Solaris 10 11/06 Release: A redundant RAID-Z configuration can now have either a single- or double-parity configuration, which means that one or two device failures, respectively, can be sustained, without any data loss. You can specify the raidz2 keyword for a double-parity RAID-Z configuration. Or, you can specify the raidz or raidz1 keyword for a single-parity RAID-Z configuration.

For more information, see Creating a RAID-Z Storage Pool or zpool(1M).