Moving a Time Machine Backup to a Time Capsule

I bought myself a Time Capsule, for a few reasons. Our wireless network at home has been pretty flaky—our AirPort Expresses (AirPorts Express?) seem to drop off the network a lot, and the “AirTunes” feature cuts in and out—and I have this vague hope that a network made up of all Apple hardware will work better. I also like the idea of always-available, wireless network-attached storage, since I’m only pretty good about remembering to hook up the external backup drive, and Rachel never remembers. Now that we’re both running Leopard, Time Machine + Time Capsule seems to add up to painless backups.

The hitch was that I’ve been running Leopard with Time Machine backups on my external LaCie drive for a few months now, and I wanted to move those backups to our shiny new 1 TB drive and maintain that backup history. When I called Apple support (our first Time Capsule was a dud) to ask how one might migrate an existing Time Machine backup from an external hard drive to a new Time Capsule, the nice man put me on hold for fifteen minutes and then came back to say it couldn’t be done.

Puh-leeze.

I know moving Time Machine backups isn’t as simple as just dragging the files from one drive to another. Because of the way the files are stored (Time Machine seems to use hard links to avoid wasting space) a regular file copy would massively inflate the size of your archive, and possibly screw up metadata, too. But surely Apple must have recognized that disks fail, archives grow, and people buy new hardware! There must be a way to move a Time Machine backup.

And there is! I found the solution on the discussion forums for SuperDuper, so that’s the software I used to accomplish the move. It’s possible that Apple’s DiskUtility would do the trick as well, but I didn’t try that. After going through it myself, I thought I’d gather the instructions in one place.

Here’s how to move a Time Machine backup from an external drive to a new Time Capsule:

  1. Hook up the external drive where you store your Time Machine backups, and do one more backup, just to be safe, by choosing “Back Up Now” from the Time Machine menu on the menu bar.
  2. Make sure your computer has a name in System Preferences -> Sharing or else your first Time Capsule backup will fail. This would be annoying later on.
  3. Set up your Time Capsule using the AirPort Utility. When you’re done, you should be able to see the Time Capsule under Shared in the sidebar of a Finder window:
  4. Mount the Time Capsule drive, by selecting the Time Capsule in the sidebar, and then, if necessary, clicking the Connect As… button and entering your Time Capsule password (that you set up in the AirPort Utility).

    You should then see a folder called Data. This represents the internal disk in your Time Capsule.

    Double-click on the folder to open it; it should be empty.
  5. Open the Time Machine preference pane (by choosing Open Time Machine Preferences… from the Time Machine menu) and click Change Disk… Choose your new Time Capsule from the list.
  6. From the Time Machine menu, choose Back Up Now to force Time Machine to start backing up to your Time Capsule. Once it starts whirring along, check out the Finder window that was showing the contents of your Data folder. Very soon you should see a file appear in that window whose name ends with .sparsebundle. Once you see that file, cancel the Time Machine backup—we were only using it to create the sparse bundle file. Once it stops, turn Time Machine off.
  7. Download SuperDuper, which is a pretty nifty backup and disk copying program. The free version is all you’ll need, but if you like it, you might consider buying the full version to support the fine people who made it possible.
  8. Double-click the sparse bundle file that you saw created earlier. This should cause a new drive to mount on your desktop, called Backup of your computer name.
  9. Launch SuperDuper. Set it to Copy your old backup drive to Backup of [your computer name] using Backup – all files. Click the Options… button, and choose Erase backup, then copy.

    Double check that your old backup drive is the source (on the left) and your Time Capsule is the destination (on the right). I mean, seriously. Then, take a deep breath, and push Copy Now.

  10. Go kill some time! This will take a while. My 200 GB of backups took about eight hours, copying from a FireWire 800 drive to a Time Capsule over wired Ethernet.
  11. When it finally finishes, go back into your Time Machine preferences and make sure your Time Capsule is still selected as the backup drive. Now, Enter Time Machine and verify that your backup history is still present. Voila!
  12. At this point, I recommend doing one more Back Up Now just to make sure everything’s working properly. This first backup after the copy will take a long while during the Preparing… phase. I’m not sure why. After that, you should be in business.

Hope this helps someone else!

Moving a Time Machine Backup to a Time Capsule