Tutorial on Moving a Time Machine Backup Drive
I've got a 1TB external drive for my Time Machine backups, but I know that someday soon, I'll need to upgrade it to larger space. When I do, I'll probably go with a very large drive system - say 4TB or more, and I want to move all my old Time Machine data to the new disk. I've done this a few times in the past, but I wanted to have a single place where I had all the instructions so I didn't have to worry about forgetting what sites I used, etc.
So here it is:
- After attaching, formatting (Mac Journaled), and naming the new drive, launch Time Machine and switch it off.
- Unmount the current Time Machine drive by dragging it to the Trash. Remount it by either turning it off and then on again, or mounting it with Disk Utility. You do this so it loses its Time Machine icon and appears with the typical orange external drive icon.
- Launch Disk Utility, select the old drive, and click on the Restore tab.
- Drag the Time Machine partition from the old drive to the Source field in the Restore tab. Drag the new drive’s partition (assuming there’s just the one partition) to the Destination field.
- Enable the Erase Destination option and click the Restore button.
- Wait while Disk Utility does its job (this can take several hours).
- When the job is done you’ll see two identical volumes on the Desktop. Unmount and disconnect the one that shows a capacity of 500GB (the old drive).
- With the new drive mounted, open Time Machine and switch it on. Click on Select Disk and direct Time Machine to the new drive that contains your copied Time Machines backup.
Time Machine should do the right thing and use that drive for its backups. Should you need to restore you’ll find that all your old backed up data is on this new drive.