

Your Mac will recognize the added hardware, and a window will appear, asking you whether you want to use the drive to back up with Time Machine. If you already know that your hard drive is compatible, just hook it up.
If not, you’ll have to reformat the drive: Click the Erase tab, choose Mac OS Extended (Journaled) from the Format pop-up menu, and click Erase.įor more information, see “ How to format a hard drive.” If the disk’s Format reads ‘Mac OS Extended (Journaled)’, you’re good to go. At the bottom of the window, you’ll see information about it. In the left-hand column of the Disk Utility window, select the disk that you want to designate as your Time Machine backup. If in doubt, connect the hard drive to your Mac and open OS X’s Disk Utility (in the /Applications/Utilities folder). Once you have an external drive, confirm that it’s properly formatted for the Mac.
