Use the Add ( +) option to create a new partition and choose the Name, Format, and Size for each partition by selecting it in the diagram. Select your external drive from the sidebar and click the Partition button.

If you can't find it, press Cmd + Space to search for Disk Utility using Spotlight.

Then go to Applications > Utilities and launch Disk Utility.

Video also covers setting it up with TimeMachine. Connect your external hard drive to your Mac. A video tutorial on how to format your externalharddrive so it works with your Mac.If you can spare more space, definitely do so. However, you shouldn't go smaller than double the size of your Mac.įor example, if you have a 128GB MacBook, you should allocate at least 256GB for Time Machine backups. If you don't want years' worth of backups, you can reduce this size as you see fit. We recommend that you allow two to four times the size of your Mac's internal drive. When you partition your hard drive, you get to choose how much space to allocate for your Time Machine backups. You can make a Time Machine backup after partitioning the drive, but your backup history will restart from that point forward. Step 1: Connect your time machine external hard drive to your Mac and then launch the disk utility by searching for it in the search bar of your Mac. That means you may lose any existing Time Machine backups. Unfortunately, creating a new partition often erases your external drive.

External hard drive time machine format