Disk Utility RAID Controls on Your MacBook
RAID, Redundant Array of Independent/Inexpensive Disks, is actually what it says. In English, a RAID set is a group of multiple separate disks, working together as a team. You can set up a RAID array on your MacBook. RAID can
Improve the speed of your system
Help prevent disk errors from compromising or corrupting your data
The RAID controls within Disk Utility are shown here. (Note that the Disk Utility toolbar is turned on as well, just to show you what it looks like.)
To set up a RAID array in Mac OS X, follow these steps:
From the RAID tab of Disk Utility, click and drag the disks from the list at the left to the Disk box at the right.
Click the RAID Type pop-up menu to specify the type of RAID that you need.
Striped RAID Set: Choosing this can speed up your hard drive performance by splitting data between multiple disks.
Concatenated RAID Set: Choosing this allows several volumes (or even multiple disks) to appear as one volume within Lion.
Mirrored RAID Set: Choosing this increases the reliability of your storage by creating a mirror backup of that data across multiple disks.
Click in the RAID Set Name field and type the name for your RAID set.
From the Volume Format pop-up menu, choose a format for the volumes.
Always use Mac OS Extended or Mac OS Extended (Journaled) from the Volume Format list unless you have a specific reason to use the MS-DOS File System (for compatibility with PCs running Windows). Journaling helps reduce the amount of disk fragmentation and also helps speed up your hard drive’s performance.
Click the Create button.