Move Time Machine Backups to a New Hard Drive (OS X Leopard)

Transfer Time Machine Backup to a Larger Drive

Time Machine
Slide the Time Machine switch from ON to OFF before cloning the current backup drive. Screen shot courtesy of Coyote Moon, Inc.

When your Time Machine backup runs out of room, it may be time to think about a larger hard drive to store your Time Machine backups. Adding or replacing your current Time Machine hard drive is simple enough, but what if you want to move your current Time Machine backup to the new drive?

If your Mac is running Leopard (OS X 10.5.x), the process for moving your Time Machine backup is bit more involved than if you're using Snow Leopard (OS X 10.6) or later, but it's still easy enough that anyone can do it. You can move the backup data and have a fully functional Time Machine drive, with all of your existing backups, ready to take advantage of the large space a new hard drive may offer.

If your Mac is running Snow Leopard (OS X 10.6.x) or later, please follow these instructions:

Moving Time Machine to a New Hard Drive under OS X 10.5

Moving your Time Machine backup to a new hard drive under Leopard (OS X 10.5) requires that you make a clone of the existing Time Machine drive. You can use just about any of the popular cloning tools, including SuperDuper and Carbon Copy Cloner. We're going to use Apple's Disk Utility to clone the Time Machine hard drive. Disk Utility is a bit more cumbersome than the third-party utilities, but it's free and it's included with every Mac.

Preparing the New Hard Drive to Be Used for Time Machine

  1. Make sure your new hard drive is connected to your Mac, either internally or externally. This process will not work for networked drives.
  2. Start up your Mac.
  3. Launch Disk Utility, located at /Applications/Utilities/.
  4. Select the new hard drive from the list of disks and volumes in the left side of the Disk Utility window. Be sure to select the disk, not the volume. The disk will usually include its size and possibly its manufacturer as part of its name. The volume will usually have a simpler name; the volume is also what shows up on your Mac's desktop.
  5. Time Machine drives running under OS X 10.5 need to be formatted with either the Apple Partition Map or the GUID Partition Table. You can verify a drive's format type by checking the Partition Map Scheme entry at the bottom of the Disk Utility window. It should say Apple Partition Map or GUID Partition Table. If it doesn't, you will need to format the new drive.
  6. The drive also needs to be using Mac OS Extended (Journaled) as the format type. You can check this by selecting the volume icon for the new drive in the drive list. The format type will be listed at the bottom of the Disk Utility window.
  1. If either the format or the partition map scheme is incorrect, or there is no volume icon for your new hard drive, then you will need to format the drive before proceeding.WARNING: Formatting the hard drive will erase any data on the drive.
    1. To format the new hard drive, follow the instructions in the guide below, and then return to this guide:
    2. Format Your Hard Drive Using Disk Utility
    3. If you want the new hard drive to have multiple partitions, follow the instructions in the guide below, and then return to this guide:
    4. Partition Your Hard Drive With Disk Utility
  2. Once you finish formatting or partitioning the new hard drive, it will mount on your Mac's desktop.
  3. Right-click (or control-click) the new hard drive icon on the desktop, and select Get Info from the pop-up menu.
  4. Make sure that 'Ignore ownership on this volume' isn't checked. You'll find this check box at the bottom of the Get Info window.

Preparing Your Current Time Machine Drive to be Cloned

  1. Launch System Preferences by clicking the System Preferences icon in the Dock, or selecting System Preferences from the Apple menu.
  2. Select the Time Machine preference pane.
  3. Slide the Time Machine switch to Off.
  4. Return to the Finder and right-click your current Time Machine hard drive's icon.
  5. From the pop-up menu, select Eject "Drive Name," where Drive Name is the name of your current Time Machine hard drive.
  6. Reboot your Mac.

When your Mac restarts, your current Time Machine hard drive will mount as usual, but your Mac will no longer consider it to be a Time Machine drive. This will allow the Time Machine hard drive to be successfully cloned in the next steps.

Clone Your Time Machine Backup to a New Hard Drive

  1. Launch Disk Utility, located at /applications/utilities/.
  2. Select the drive you're currently using for Time Machine backups.
  3. Click the Restore tab.
  4. Click and drag the Time Machine volume to the Source field.
  5. Click and drag the new hard drive volume that you will be using for the new Time Machine drive to the Destination field.
  6. Select Erase Destination.WARNING: The next step will fully erase any data on the destination volume.
  7. Click the Restore button.
  8. The cloning process will start. This can take a while, depending on the size of your current Time Machine backup.

During the process of cloning, the destination disk will be unmounted from the desktop, and then remounted. The destination disk will have the same name as the startup disk, because Disk Utility created an exact copy of the source disk, down to its name. Once the backup process is complete, you can rename the destination disk.

Selecting the New Hard Drive for Time Machine's Use

  1. Once the copying is complete, return to the Time Machine preference pane and click the Select Disk button.
  2. Select the new hard disk from the list and click the Use for Backup button.
  3. Time Machine will turn back on.

That's all there is to it. You're ready to continue using Time Machine on your new, spacious hard drive, and you didn't lose any of the Time Machine data from the old drive.

If you would like to increase the reliability of your Time Machine backups, consider upgrading to OS X Mountain Lion. With Mountain Lion, Time Machine gained support for using multiple backup drives. You can find out more at: How to Set Up Time Machine With Multiple Drives​.​