Transfer Time Machine backups from one backup disk to another

You can move a Time Machine backup from one disk to another, then use the new disk to continue your Time Machine backups.

Connect both backup disks to your Mac

Start by making sure that both your old backup disk and your new backup disk are connected to your Mac and mounted. That means they should both appear on your desktop or in the sidebar of Finder windows.

If your old or new backup disk is an AirPort Time Capsule or other networked backup disk, connect it to your Mac using Ethernet for the fastest transfer speed.


Check the format of your new backup disk

Follow these steps only if your new backup disk is an external USB, Thunderbolt, or FireWire drive directly connected to your Mac. (Skip them if your new backup disk is a network backup disk.)

  1. Open System Information, then select Storage in the sidebar. 
  2. From the list of storage devices on the right, select the name of your new backup disk. If the File System shown for that disk is ”Journaled HFS+” and the Partion Map Type is ”GPT (GUID Partition Table),” your new disk is formatted correctly for Time Machine. Skip to the next section, below.
  3. If your disk isn't formatted correctly for Time Machine, use Disk Utility to erase (format) the disk. When Disk Utility asks for the format and scheme, choose Mac OS Extended (Journaled) as the format and GUID Partition Map as the scheme.


Set permissions on your new backup disk

Follow these steps only if your new backup disk is an external USB, Thunderbolt, or FireWire drive directly connected to your Mac. (Skip them if your new backup disk is a network backup disk.)

  1. Select your new disk in the Finder, such as by clicking its icon on your desktop or in the sidebar of a Finder window. 
  2. Choose File > Get Info from the menu bar. An info window for your disk opens.
  3. Click the disclosure triangle  next to Sharing & Permissions to show the settings in that section.
  4. If the lock at the bottom of the window is closed , click the lock and enter your administrator name and password.
  5. Make sure that the ”Ignore ownership on this volume” checkbox is unselected.


Turn off Time Machine

  1. Open Time Machine preferences from the Time Machine menu in the menu bar. Or choose Apple menu  > System Preferences, then click Time Machine.
  2. Deselect ”Back Up Automatically” or click the Off/On switch, depending on what you see in Time Machine preferences.


Copy backup data to your new disk

  1. In the Finder, open a new window for each of your backup disks, so that you can drag files between them.
  2. Depending on the type of backup disk you've been using, your old backup disk should have one of these files at the top level of the disk:
    • A file that ends with .sparsebundle
    • Or a folder named Backups.backupdb
      If you have this folder, you can transfer your backup only if your new disk is an external USB, Thunderbolt, or FireWire drive connected directly to your Mac. It can't be one of the other types of disks you can use with Time Machine.
  3. Drag that file from your old backup disk to the top level of your new backup disk.
  4. Enter your administrator name and password, if prompted, then wait for the copy to complete.


Select your new backup disk in Time Machine

After copying the old backup file to the new disk, select the new disk in Time Machine preferences and make sure that Time Machine is turned on. All the old backups will then be available from the new disk, and new backups will be saved to that disk.

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