Restore Entire Drive

My ancient iMac (Retina 5K, 27-inch, Late 2015) running macOS 12.7.1 Monterey has two internal drives (which are NOT configured as a Fusion Drive) named:

  1. MacOS (Original 128GB SSD APFS) 20.11 GB Free
  2. MacUsers (6 TB WDC WD6001FZWX-00A2VA0 Journaled HFS+ GUID Partition Table) 1.74 TB Free

The operating system and applications are installed on MacOS whereas MacUsers contains data files. I have two administrator accounts, one of which uses MacUsers for its entire home directory (configured via System Preferences → Users & Groups → Advanced Options).

I use Time Machine on an APFS external USB drive (TMA) to backup both internal drives together.

MacUsers is failing and I will replace it with a Samsung 870 QVO SATA III SSD 8TB 2.5"

How do I restore the contents of MacUsers (only) from TMA to the new SSD?

Can I use either of these GUI utilities and if so exactly how do I choose the entire—and only—MacUsers drive as the source:

  1. Time Machine
  2. Migration Assistant

Or do I have to use the command line as described here:

Thank you.

That seems to be a complicated set-up. I don’t have a recommendation for you but thought I should describe my experience restoring from Time Machine.

My 2019 iMac had unknown problems that slowed it down severely. I decided to do a clean install of Ventura using a bootable USB memory stick. During the process I erased the internal drive. This is supposed to check the drive and repair any faults and seemed to work.

At the end of the installation I had the choice of migrating data from another Mac or from Time Machine. I chose Time Machine and after many hours the system was configured as intended. In effect it was restored to its previous configuration with all data and apps.

Unfortunately the iMac was still slow and I have since retired it and now use an M2 Macbook Air and monitor (described in a seperate discussion) as my main computer.

The benefit of this configuration is that the operating system and applications run fast because they are on the SSD. And, I didn’t mention it, but I put 24GB of RAM into this iMac so perhaps I cut down on virtual memory swapping. Other than for Photos, putting the data on spinning rust isn’t a bottleneck.

So, I get the most of the benefit of a fully solid-state computer at a very low cost, particularly for 2016 when I put it together.

Nello, this may or may not be relevant. When migrating to a new machine, I have run into problems and called Apple Support for advice. It appeared (I’m not 100% sure, because Support had me do different things than I had been doing, and this is not something you want to do 10 times to figure out what works and what doesn’t) that restoring from Time Machine did not work, and that Migration Assistant did work. All I can safely say is that when I explained what I was trying to do, Support said “Open Migration Assistant…”


This makes perfect sense. As I understand it, restoring from Time Machine is going to pretty much clone your Data volume to the system (or clone everything if this is an old enough version of macOS).

That’s great if the backup was made from the same computer. But if it’s a new computer, where the hardware (and probably also the macOS revision) is different, then some of the content of that TM backup will be incompatible with the new system.

Migration Assistant, on the other hand, is designed for the purpose of moving data to a new and potentially incompatible system (different hardware, different macOS revision, etc.) and includes features that are supposed to omit or upgrade various system files that would otherwise break the new machine.

FWIW, I’ve done both over the years, but I only restore to the same machine that made the backup. I migrate to different computers.

And today, with the signed system volume, I believe the prevailing wisdom is that you should migrate after a system reinstallation even to the same computer.