How to Create a software RAID in Mac OS 10.11

Launch Terminal

In the Terminal.app, type the following:

diskutil list

Find and note the external, physical drives that you want to include in the RAID.

E.g., disk0 and disk4

Decide which RAID mode you want - striped (RAID 0) or mirrored (RAID 1).

In the Terminal.app, type the following: for RAID 0:

diskutil appleraid create stripe [Array Name] JHFS+ disk_ disk_


For example: diskutil appleraid create stripe YOUR-RAID-NAME JHFS+ disk0 disk4

or



In the Terminal.app, type the following:for RAID 1:


diskutil appleraid create mirror [Array Name] JHFS+ disk_ disk_


For example: diskutil appleraid create mirror YOUR-RAID-NAME JHFS+ disk0 disk4

Then press Enter.

The Disk Utility will create the RAID.