Apple Xserve RAID: Using RAID 1.2 Admin and Disk Utility - Manual (Page 22)

22 Chapter 2 Working With RAID Arrays
To add software RAID to two or more arrays:
1 Open Disk Utility on the host system and click the RAID tab.
2 Drag the arrays you want to stripe or mirror from the left side of the window to the
Disk list at the center of the window.
Note: You must use two or more arrays to create a software RAID set.
3 Select the arrays in the Disk list.
4 Choose Stripe or Mirror from the RAID Scheme pop-up menu.
5 Enter a name for the new software RAID volume.