The first time you use Time Machine, you will need to select a disc to use for your backups. You can use an internal hard drive, an external hard drive, or a partition on one of your existing hard drives.
Although you can select a drive partition, be careful if you choose this option. In particular, avoid choosing a partition that resides on the same physical disc as the data you will back up. For example, if you have a single hard drive (perhaps in a MacBook or a Mini) that you have partitioned into two volumes, I don’t recommend using that second volume for your Time Machine backup. Both volumes reside on the same physical drive; if the drive should fail, there’s a high probability that you’ll lose access to both volumes, which means you’ll lose your backup as well as your original data. If your Mac has a single internal hard drive, I recommend using an external hard drive as your backup disc.
Select Your Backup Disc
- Click the ‘Choose Backup Disc’ button.
- Time Machine will display a list of discs you can use for your backup. Highlight the disc you want to use, and then click the ‘Use for Backup’ button.

