If you can't back up or restore your Mac using Time Machine

Check these things if you see an alert that Time Machine is unable to back up your data, or if you can't select your backup disk in Time Machine preferences.

System Requirements

Before using Time Machine, you need a backup drive to copy your backed up files onto. Time Machine is designed to work with the following:

  • External drives directly connected to the USB, FireWire, or Thunderbolt ports on your Mac 
  • The built-in drive of an AirPort Time Capsule
  • A USB drive connected to the USB port of a Time Capsule or AirPort Extreme 802.11AC base station
  • A networked volume served by OS X Server using Apple File Protocol (AFP)

If your backup drive is connected differently, it might not work. Check with the device manufacturer for compatibility and connection information.

Check these things:

If you're unable to use Time Machine and your configuration meets system requirements, check each of these parts of your backup.

Check your Mac

  1. Make sure OS X is up to date by using Software Update.
  2. Restart your Mac and see if the issue continues.

Check your AirPort device

  1. If you're using an AirPort Time Capsule or AirPort Base Station, check to make sure its firmware is up to date by using AirPort Utility.
  2. Restart your Time Capsule or AirPort Base Station and see if the issue still happens. To restart your device, simply unplug it from AC power for five seconds, then plug it back in.

Check your network connection

If you back up your files to a server, or to a drive connected to your Time Capsule or AirPort Base Station, make sure you're connected to the same network as your backup. You can select your wireless network from the Wi-Fi menu

Check your backup

If you back up your files to a server, or to a drive connected to your Time Capsule or AirPort Base Station, you can check to make sure your current Time Machine backup doesn't have any issues that could prevent backing up.

  1. Hold down the Option key and click the Time Machine icon in the menu bar on your Mac 
  2. Choose Verify Backups from the Time Machine menu.

If Time Machine finds an issue with your backup, it displays an alert message with guidance after verification is finished. Follow the onscreen instructions to try to correct the issue with your backup.

Check your drives

If you can't back up, check both your backup drives and any drives you're backing up (like your startup disk). 

Is your backup drive turned on and connected?

If you're using a drive connected to a port on your Mac, Time Capsule, or AirPort Base Station, make sure it's powered on. If you're using a USB hub or a similar device, try connecting the drive directly to your Mac, Time Capsule, or AirPort Base Station.

Is your backup drive formatted correctly?

When you select a drive to use with Time Machine, your Mac automatically prompts you if you need to reformat it.

  • If you're using an external drive connected to your Mac, use Disk Utility to make sure that your backup drive is formatted as HFS+ Extended (Journaled) and that the partition type is GUID Partition Table (GPT).
  • If you're using a Time Capsule, formatting the drive from Time Machine preferences automatically formats the drive as HFS+ Extended (Case Sensitive, Journaled) with a GUID Partition Table (GPT).

Important: Reformatting a drive erases all of the data currently stored on that drive. Move any important files to another drive before erasing your backup drive.

Does your startup disk or backup drive need directory repair?

You can use Disk Utility to verify your startup disk, your backup drive, and any other drives you're trying to back up. Turn off Time Machine, then connect any drives you're using as part of your backup. 

  1. From the Apple menu, choose System Preferences.
  2. From the View menu, choose Time Machine.
  3. Set Time Machine to Off to disable Time Machine backups.
  4. Connect your backup drive to your Mac.
  5. Open Disk Utility located in /Applications/Utilities.
  6. In Disk Utility, locate and select your drive in the sidebar.
  7. Click Verify Disk, or click Repair Disk.

You can turn Time Machine back on after your drive is verified as ok, or repaired successfully.

If Disk Utility finds issues it can't repair, see Using Disk Utility to verify or repair disks for more information on the next steps to try. It's possible the drive might need to be reformatted, or the backup is damaged.

Is your backup drive's firmware out of date?

If you're backing up to an external drive, check with the drive manufacturer to make sure the drive's firmware is up to date. You can find the firmware version for the drive by connecting it to your Mac, then looking in the devices section of System Information.

Learn more

For more information about backing up your files, open Time Machine in System Preferences, then click the Help button   at the bottom of the window. These articles also include more information about Time Machine:

OS X

AirPort Time Capsule

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