How to set up Time Machine on an external drive

💡 Need to know

• Choose a drive with plenty of room. More storage means Time Machine® can keep a longer history of backups.
• Check what’s already on the drive. Your Mac® may need to erase or reformat it during setup.
• Encryption is worth considering. It adds password protection to your backups.
• Once it’s set up, Time Machine takes over. Your Mac can automatically back up whenever the drive is available.

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Losing a file is usually the moment everyone wishes they’d set up a backup sooner. Time Machine makes that job pretty painless: connect an external drive, set it up once, and your Mac can handle the backups from there.

At Asurion, we help millions of people protect the files and devices they rely on every day. Here’s how to choose the right external drive, set up Time Machine, and make sure your Mac is actually backing up what matters.

Choose and prepare your external drive

Before you can set up Time Machine, you need to select an external drive to use. Consider these key factors when you make your purchase:

• Capacity: How much the drive can store. Look for 1 TB to 2 TB for general use and 4 TB or more if you have lots of large files or entire computer systems to back up.
• Connection type: Check the available ports on your MacBook. Common fast transfer connection types for external drives include USB-C and Thunderbolt.
• SSD vs HDD: Solid State Drives (SSDs) are best for running apps or travel, not backups. Opt for an external Hard Disk Drive (HDD) for system backups.

Only plan to use this specific Time Machine external hard drive for backups, not general file storage. Time Machine automatically deletes old backups to make room for new ones when your drive runs out of space, which could lead to your loose files on the drive getting lost.

Before investing in an external drive, though, look into how iCloud backup compares to Time Machine. You may choose to use iCloud for your backups instead.

Set up your external drive for Time Machine

Once you have your external drive ready, follow these instructions to set up Time Machine.

1. Plug in your external drive to your MacBook.
2. Open System Settings from the Apple menu.
3. Choose General > Time Machine > Add Backup Disk.
4. Select your external drive and choose Set Up Disk.
5. If there are files already on the external drive, your Mac may ask whether you want to delete them to use the drive for Time Machine. Erase the drive.
6. Choose whether you want to turn on Encrypt Backup to secure your backups behind a password.

After you complete these steps, your Mac will automatically start backing up your files to the external hard disk for Time Machine.

You may wonder on a MacBook Pro how to use Time Machine with a USB stick. If the USB stick has sufficient storage to support backups, simply plug it into your MacBook and set it up in Time Machine.

When you’re setting up a new Mac after switching devices, you can use the Time Machine backups on your external drive to quickly transfer your files.

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Troubleshoot common Time Machine problems

If you run into an issue while setting up Time Machine and an external hard drive, try these troubleshooting solutions.

• You don’t see the Time Machine backup external drive: Try unplugging and replugging the drive into your Mac, or using a different port. Test out the drive on another device to make sure it’s working.
• There are already files on the drive: Copy the files to another drive or onto your computer before erasing the drive during the Time Machine setup process.
• Stuck on “Preparing Backup”: Stop the backup, turn off backup using Time Machine on your Mac, and delete files ending in .in-progress from your backup drive in Finder. Empty your trash and turn Time Machine back on.
• Not enough storage to back up your computer: Consider deleting files or upgrading your drive for more storage if your Mac is running low on storage.

You can also add, remove, or exclude specific drives and folders from backups in Time Machine settings.

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FAQ

Can Apple Time Machine back up to an external drive?

Yes, Time Machine lets you automatically back up your MacBook to a connected external drive.

Is it safe to delete Time Machine backups on an external hard drive?

If you no longer need old Time Machine backups from an external hard drive, it is safe to delete them. Just make sure you have copies elsewhere of any files, apps, or other data from the backups that you still need.

Does Time Machine back up everything on a Mac?

Time Machine backs up most files, apps, settings, and other data on your Mac. You can also exclude specific files, folders, or drives you don't want to back up.

How do I restore files from a Time Machine backup?

Connect your Time Machine drive, open Time Machine, find the file or version you want, then restore it. You can also use a Time Machine backup when transferring data to a new Mac.