An important application in your MacBook maintenance toolbox is Disk Utility, which you find — no surprise here — in the Utilities folder within your Applications folder. When you first run this program, it looks something like the following, displaying all the physical disks and volumes on your system.


The Disk Utility application has its own toolbar that you can toggle on and off. Click Window→Hide/Show Toolbar to display or hide the toolbar, or Window→Customize Toolbar to select which icons inhabit the Disk Utility toolbar.

The volume tree structure on the left of the Disk Utility window lists both the physical disks and the partitions that you’ve set up. A partition is nothing more than another word for volume, which is the formatted section of a disk that contains data. A single physical hard drive can contain several partitions.

The information display at the bottom of the Disk Utility window contains data about both the volumes and the partitions on your hard drive.

Clicking the drive labeled 500.11 GB (the physical external FireWire hard drive at the top of the tree) displays a description of the drive itself, including its total capacity, connection bus (the interface it uses), and whether the drive is internal or external (connection type).


Clicking the tree entry for Time Machine Backups, however — that’s the name of the partition — displays information about the type of formatting, the total capacity of the partition and how much of that is used, and the number of files and folders stored on the partition.