Disk Utility, a free application included with Mac OS X, is a multipurpose, easy-to-use tool for working with hard drives, SSDs, and drive images. Among other things, Disk Utility can erase, format, repair, and partition hard drives and SSDs, as well as create RAID arrays. In this guide, we'll use Disk Utility to erase a volume and format a hard drive.
Disk Utility works with disks and volumes. The term 'disk' refers to the drive itself; a 'volume' is a formatted section of a disk. Each disk has a minimum of one volume. You can use Disk Utility to create a single volume or multiple volumes on a disk.
It's important to understand the relationship between a disk and its volumes. You can erase a volume without affecting the rest of the disk, but if you erase the disk, then you erase every volume that it contains.
Disk Utility has three main sections: a toolbar that spans the top of the Disk Utility workspace; a vertical pane on the left that displays disks and volumes; and a work area on the right, where you can perform tasks on a selected disk or volume.
Let's Get Started
- Launch Disk Utility, located at /Applications/Utilities/.
Since you will use Disk Utility for system maintenance purposes as well as for working with hard drives, I recommend adding it to the Dock. Right-click the 'Disk Utility' icon in the Dock, and select 'Keep in Dock' from the pop-up menu.