You can configure two global hot-spare drives to protect data on mirrored RAID volumes. If one of the drives in a RAID 1, RAID 1e, or RAID 10 mirrored volume fails, the on-board RAID controller will replace the failed drive automatically with a hot-spare drive and then resynchronize the mirrored data.
Use the sas3ircu utility to add global hot spare drives. For instructions, see the 12Gb/s SAS Integrated RAID Configuration Utility User Guide available from https://www.broadcom.com/support/oem/oracle/sparc-t/sparc-t7-series.
You can also use the raidconfig utility included in the Oracle Hardware Management Pack to create hot-spare drives.