Move Time Machine Backups to a New Volume

I used up all the room on my 160 GB Time Machine volume, so I picked up a new Western Digital hard drive  to increase my backup capacity. How do I transfer my existing Time Machine backup from the old, maxed-out disk to the new high capacity drive? I'm running Mac OS X 10.5 Leopard; the steps might be different for other versions of OS X. As it turns out, you can't just drag your old Time Machine backups to the new disk using a Finder copy. Time Machine creates all kinds of "hard links" to the files that aren't changed. If you just copy these files in the Finder, you'll create full copies of all the links, ballooning the size of your backup exponentially. Instead, you need to use a Block Copy operation. This requires that you completely erase the new drive as part of the copy procedure. Here's an overview of the steps I followed to transfer my Time Machine backups. Note that I use both "drives" and "volumes" to refer to logical disk drive volumes.

1. Ensure that the system isn't trying to work with your Time Machine drives.
• Turn off Time Machine & stop using the original drive for backups.
• Tell Spotlight not to index your Time Machine drives.
2. Perform a Block Copy of your original Time Machine database to the new drive.
3. Tell Time Machine to use the new drive as the Time Machine backup drive.

It took me a while to get this to work, as I ran into some permissions issues. To start, I found this tip for Mac OS X 10.5: Move Time Machine backup to another drive, which recommended using a Disk Utility Restore to copy the data. Unfortunately, I get the message:

Could not restore - Operation not permitted

even with Time Machine turned off. It looked like the Mac was trying to access the new drive while I was doing the backup. So, I turned Time Machine off completely, using these steps:

 Deactivate Time Machine

1. Open Time Machine Preferences.
2. Turn Time Machine OFF using the slider switch.
3. Click [Change Disk...].
4. Select None.
5. Click [Use for Backup]

These steps will prevent Time Machine from trying to access the drive at any time during the (potentially) lengthy period it requires to move your data. I also recommend turning of Spotlight indexing for the Time Machine drives (not a bad idea in general, because you really don't need to index the backups with both Time Machine & Spotlight).

Turn off Spotlight Indexing for your Time Machine drives

1. Open Spotlight preferences (System Preferences > Spotlight).
2. Select the Privacy tab.
3. Add your Time Machine disks to the Prevent Spotlight from searching these locations list box using the Add (+) button in the lower left, or dragging the disk icon from the Finder to the list box.

[Antonio notes in the comments: Boot from the Leopard DVD so you can perform all of the following steps without having to make of the any adjustments to Spotlight described above.]

Block Copy the Time Machine Backups using Disk Utility Restore

I used the Disk Utility Restore feature to move my data. It failed the first few times because I neglected to erase the destination disk, to allow Disk Utility to use Block Copy mode. Here's how to do it:

1. Open Disk Utility.
2. Select the original Time Machine volume.
3. Click the Restore tab.
4. Drag the icon for the original Time Machine volume to the Source: field.
5. Drag the icon to for the new Time Machine volume to the Destination: field.
6. Click Erase destination -- this is important because it addresses the permissions issues that plagued me, and also allows Disk Utility to use a block copy mode.
7. Click [Restore].

Note that you'll need to authenticate to perform these steps. The end result: it took about 7 and a half hours to restore 150 GB of data on my 2.4 G Hz MacBook Pro. More than half of this time was the verification pass. Also, the name of the source volume was applied to the destination, which was a little confusing. Now, it's time to point Time Machine at the new drive.

1. Open Time Machine Preferences and authenticate, if required.
2. Click [Choose Backup Disk...].
3. Select the disk you prepared (I renamed it with a more descriptive name).
4. Click Click [Use for Backup].
5. Confirm the Time Machine slider is set ON.

I selected a folder that has had lots of changes, and opened the Time Machine "lost in space" interface: it's got backups for the last six months -- it looks like it worked.

Carbon Copy Cloner

I took a close look at the comments on the tip Move Time Machine backup to another drive and it looks like Carbon Copy Cloner (CCC) is another option. Since the Disk Utility approach didn't work the first few times, I also tried using CCC to copy the data via block mode. Here's what I did in Carbon Copy Cloner 3.1.2

1. Selected the old Time Machine volume as the Source Disk.
2. Selected the new Time Machine volume as the Target Disk.
3. For Cloning options:, select Backup everything,
4. Check Delete itmes that don't exist on the source (this is required to use block-copy mode, which is recommended). Note that this also erased today's Time Machine backup from the new volume, but that's not a problem.
5. Click [Clone].

Now it's time to do something else, as this process is going to take quite a while. In fact, it didn't work at all: I checked the CCC Log and everything was failing, and CCC was using rsync to move the data, not block mode. So, I canceled, and instead used Disk Utility with the Erase destination option, as described above.

Super Duper

[Update] Super Duper is another disk copy tool for the Mac, and is now my favorite choice for Time Machine transfers. To use Super Duper to move your Time Machine database to a new volume:

1. Turn off Time Machine (as described above) to avoid permissions issues. Note that SuperDuper will automatically turn off SpotLight and turn in back on, if required.
2. Start Super Duper.
3. Select the Time Machine volume you want to Copy from and the new volume you want to copy to.
4. Select using Backup - all files
5. Review the What's going to happen? text for details on what Super Duper is about to do.
6. Click [Copy Now] and authenticate if required.
7. Click [Copy] to confirm this is what you want to do.

Note that this process will erase the destination or target volume. Also note how Super Duper tells you exactly what it's going to do before it does it, and what it's doing as it works away. I really like this program.

Use Your New Time Machine Volume


Now that your Time Machine database is on a new volume, you need to tell Time Machine to use it.

1. Open System Preferences > Time Machine
2. Click the lock in the lower left corner to make changes, and authenticate.
3. Click [Change Disk...]
4. Select the new Time Machine disk.
5. Click [Use for Backup]

This will turn Time Machine back on.

Other Resources

• Mac Forums: Move Time Machine Backup to new drive.
• Carbon Copy Cloner
• Super Duper