Apple Xserve RAID - Manual (Page 66)

Planning RAID Storage for the Xserve RAID System 67
RAID 1 Schemes
You can use RAID 1 several ways on a four-drive system, depending on how you divide the
drive modules between the RAID controllers and how you mirror the data on the drives. If all
the modules are on one controller, you can have two RAID sets on one controller.
If two modules are on each controller, you can create one RAID set on each side.
RAID 3 and 5 Schemes
You can configure the system using RAID 3 or 5 with or without a drive module designated as
a hot spare. (A hot spare is a drive that remains ready to replace any other drive that fails.
The RAID controller automatically rebuilds data from the failed drive on the hot spare.)
RAID 1
Mirror Mirror Disk 1 Disk 2
Appears
as
RAID 1
Mirror Mirror Disk 1 Disk 2
Appears
as