How to Partition a Hard Drive on a Mac

Partitioning a hard drive is beneficial if you want to use different versions of OS X or install Windows or Linux on your Mac computer.

Step 1: Back up data Back up any data on the hard drive to another drive or computer. Partitioning erases a drive.
TIP: In order to partition the startup volume, or the main hard drive of the computer, insert the Mac OS X install disc, restart the computer, and hold down the C key when you hear the startup chimes.
Step 2: Launch disk utility Go to Applications, then to the Utilities folder, and open Disk Utility.
Step 3: Select drive Select the disk you want to partition by clicking on its name in the list.
Step 4: Go to partition tab Click the Partition tab.
Step 5: Setup partition specifics Choose a volume scheme for the drive and set options for the name and size of each partition. Drag the dividers between the drives to resize them.
Step 6: Apply Click Apply to partition the drive.
FACT: Released in 1979, the 5MB ST506 was the first hard disk drive for personal computers.