Time Machine swap
Last night, I successfully swapped two hard drives that were used as Time Machine backups on two different laptops. I had a 500 GB Western Digital backing up my laptop, and my brother had a 500 GB LaCie. We decided that, since I’m going to college soon, it made more sense for me to use the more durable drive. So we wanted to swap the data.
I found information online about moving backups from an old drive to a new one, but nothing on swapping them. So, here is a step-by-step guide.
Required applications are Disk Utility (in the Utilities folder) and SuperDuper (the free version will suffice). This assumes you have enough free space on one of your computer’s internal drives. If not, you may need a third external hard drive.
As always when dealing with backups, BE CAREFUL. This worked for me, and I lost no data. I cannot, and do not, guarantee that it will work for you.
- Turn off Time Machine in System Preferences.
- Mount both disks, and determine which has the least data on it. We’ll call that disk “Drive 1” and the one with more data “Drive 2”.
- Open Disk Utility, and create a disk image large enough to hold all the data on Drive 1. Use all of the default settings except for size. Call it something like “Drive Clone”.
- Open SuperDuper. Select Drive 1 in “Copy”, Drive Clone in “to”, and “Backup - all files” in “using”. Hit Copy Now. This may take a couple hours, or much less, depending on how much data you have.
- Open Disk Utility again. Choose Drive 1 in the left-hand sidebar, and the Restore tab.
- Drag Drive 2 to “Source”, and Drive 1 to “Destination”. Leave “Erase destination” checked, and hit Restore. This can be a very lengthy process, so you may want to go get some coffee, or take a nap.
- Unmount Drive 1 once it’s finished. Congratulations, your first copy is done! Drive 1 now contains an exact replica of Drive 2. At this point, it will work as your Time Machine volume, after a little bit of addition tweaking, which I’ll go over later.
- Open Disk Utility. This time, choose Drive 2 in the sidebar, and the Restore tab again.
- Drag Drive Clone to “Source” and Drive 2 as “Destination”. Once again, leave “Erase destination” checked, and hit Restore. Again, it will take some time.
You are done copying disks (yay! finally!), but there are a couple more things to do, so that everything will run smoothly. These steps should be done on both computers, with the drive you intend to use as its backup.
- Turn Time Machine back on in System Preferences.
- Mount the disk.
- Choose “Enter Time Machine” from the Time Machine drop-down menu, or click launch it from the Dock.
- It should now load your old backups, as if nothing changed! Once you’ve verified this on both computers, you can delete Drive Clone.
- Try to do a backup now. If it works, you’re done! If it doesn’t (mine didn’t), you need one more step.
- Open Time Machine preferences again, click “Select Disk…”, and choose the drive. Try a backup again. It should work. Now, you are done.
On timing: I had a little under 50 GB of data on the smaller drive, and over 350 GB on the other. Step 4 took me about twenty minutes, step 6 took about four hours, and step 9 took about forty minutes. So, times vary greatly.
I hope this has been helpful!