How to Initialize or Erase a New or Existing Drive
When a new drive is attached or installed, OS X will prompt you to do something about it for each such uninitialized drive, as shown below.
Clicking
brings up Apple Disk Utility. It won’t do anything harmful on its own; it launches Apple DiskUtility where the choices are open.Erasing
Select the new drive at left, in this case
, then click on the tab (between and ).Choose a name (Master as shown here), then click the for more than one volume, the drive should be partitioned.
button. This creates a single volume;Confirming
After clicking the how these items preference is selected in the Finder).
button, a confirmation dialog is presented. To proceed, click . When done, the volume will appear on the Desktop with the chosen name (assuming the SIf this is a backup drive, it is generally a good idea to exclude it from Spotlight search.