I have two old Macbook Pros (late 2013, identical model). A is not needed anymore, has a broken battery and touchpad but 1 TB SSD. B is still in use by one person (for simple browser stuff that's ok) but has only 256 GB SSD (thus a system update isn't even possible anymore).

I'd like to use the 1TB SSD in the Macbook B. Besides of opening and getting the hardware stuff done, I wonder about the best strategy to do it. Of course there's a Time Machine backup from B on a NAS.

If I would simply replace the 256 GB SSD with 1 TB and restore from TimeMachine, then it's probably taking a long time due to NAS. However I should feel safe since if anything goes wrong, I can simply bring the small SSD back and everything should run as before.

So I wonder if I could just

  • clean the 1TB (how exactly don't know), so the MBP aks for a system to install/migrate from
  • switch them around (1 TB goes to B, 256 GB goes to A)
  • start MacBook B and let it migrate from A (old SSD).

What if something goes wrong? If Macbook A was started with the small SSD to serve as a migration host, will it change anything on the SSD which may prevent it from run properly when switched back?

Any other suggestions? Anything to have in mind, maybe from OS perspective?


1 Answer 1


I'd take these actions:

  • Swap out the physical SSDs.
  • Boot the working laptop (now with the 1TB) using Internet Recovery with Command (⌘)-R.
  • Install macOS and use migration assistant from the other laptop.

You could use WiFi to migrate, but best speed would come from using a data cable (Thunderbolt) to connect them.

Migration is a read only operation. Well, any writes will be a result of the system booted not the migration.

  • Thanks, so basically my 3 points. So no erasing first but booting with CMD+R? I think on 1 TB the current OS is higher than on the small one, but I would prefer to migrate clean (old OS) and then do an update later on. Don't know if the boot up will somehow write something that would prevent me from booting the small SSD (in case of Murphy).
    – Karsten S.
    Commented Nov 17, 2022 at 15:20
  • cmd + option + R Is internet recovery (newest supported os). So if you want the same os you might consider booting the old disc on the current system, then target disk mode on the 1 tb broken system. Install carbon copy cloned and cloning the 256 to the 1TB- then swap discs Commented Nov 17, 2022 at 15:29
  • 1
    If unfamiliar, TDM is connecting with a data cable between the two machines but having one pretend to be a usb disc instead of booting. All of this is safe if you are cautious and don’t mix up the discs. Commented Nov 17, 2022 at 15:30

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .