How hard is it to revert to a time machine backup?

February 7, 2021 12:47 PM

How easy is it to image a Mac laptop with an old time machine backup?

I recently took my computer to Apple for a repair. They wiped the computer and reinstalled the OS. Somewhere in my apartment I have an external hard drive with a time machine backup. I don’t know where the hard drive is, or how long it will take me to find it.

If I run the set-up process on my computer and treat it as new, and then a week later I want to use the external hard drive to recreate the most recent time machine back-up, how easy a process is that?

Is there an easy way to do it on the working laptop, or do I have to someone wipe and reinstall the OS again to have the option to use a time machine backup?

I would rather get started with the laptop tonight, but I can hold off on the set up process until I find the external hard drive, if that would save me a headache later.

posted by andoatnp to Computers & Internet (3 answers total)

Best answer: Here are the instructions for using Migration Assistant with a Time Machine backup, which you can run at any time without having to reinstall the OS. The one catch is that it will put your old, backed-up user account on the laptop, rather than integrating with the user account you’ll have been using for a week. But yes, it is easy to just run this process, start using your old, backed-up user account, and delete the new user account you’ve been using (after transferring any important files to the backed up account).
posted by ejs at 1:11 PM on February 7, 2021 [1 favorite]

Best answer: The one catch is that it will put your old, backed-up user account on the laptop, rather than integrating with the user account you’ll have been using for a week.

Yep and if they have the same username, that used to (but I don't think still does) cause namespace collision stuff, so worth keeping in mind. My suggestion would be start using it now, maybe make a temp account that you can just erase afterwards, but maybe don't start really customizing it and then wait until you find the drive.

You can open up a time machine backup and just click and drag individual stuff over, but it's usually not worth it. Only thing to know is that if your backup includes EVERYTHING (like applications as well as personal data) it may take a while but just set it up to restore overnight or during the day when you're doing something else and you should be good.
posted by jessamyn at 1:21 PM on February 7, 2021 [1 favorite]

Yep and if they have the same username, that used to (but I don't think still does) cause namespace collision stuff, so worth keeping in mind.

Can tell you from recent experience that Apple has indeed addressed this issue. Migration Assistant will make you rename the account in this case.
posted by ejs at 1:32 PM on February 7, 2021 [1 favorite]