Cloning OS X 10.12 drive from 2010 iMac to a new 2018 Mac mini

Discussion in 'macOS Mojave (10.14)' started by macuser_123, Feb 5, 2019.

  1. macuser_123 macrumors newbie

    Mar 21, 2018
    I have a 2010 iMac on 10.12, and thinking about upgrading to a 2018 Mac mini since already have external monitor, speakers, etc.

    My question is I have spent a lot of time customizing my filesystem to "T", and would prefer to just clone my existing hard drive over (or via Time Machine backup), instead of relying on Migration Assistant that I understand doesn't necessarily copy everything over, which will save a lot of time in recustomizing everything. However, the Mac mini, as I understand it, will only boot 10.14 and nothing earlier, and I cannot first upgrade my iMac to 10.14, since it will only support up to 10.13. Would it work if I clone my iMac drive over to a partition on the new Mac mini, and then from the built in Mac mini 10.14 partition or a bootable USB drive installer etc., run the 10.14 installer to do an upgrade install on the 10.13 partition, and then boot from the newly upgraded partition?

    I know a clean install is the way to go but I'm just tired of doing them.

    Thanks for any advice.
  2. oatman13 macrumors regular

    Feb 14, 2013
    Not possible; especially with the introduction of the T2 machine.
    The best path forward for you is to use System Migration and migrate your data over WiFi or preferably a Thunderbolt/USB cable.
  3. chrfr macrumors 604

    Jul 11, 2009
    The 2018 Mini requires 10.14 or later. You can't use your 10.12 installation on the Mini.
  4. macuser_123 thread starter macrumors newbie

    Mar 21, 2018
    Thanks for the reply. If you have time, could you go into a little more detail, so I can understand this fully? I did read about the new T2 chip, which I was not aware of.

    Why would the Mac not recognize a prior installation of OS X from another machine, then subsequently updated with the 10.14 installer, as a legitimate bootable OS? Does this eliminate the possibility in the future of transferring any OS installation from computer to computer via cloning or Time Machine restore?

    Would this work without the T2, or is there something fundamentally wrong about this approach in the first place?

    Also, I read that the T2 will also prevent booting from external drives; is this true? Does that dash my plans of a) getting the smallest drive possible on the mini and planning to upgrade later with a cheaper external drive if I need more space and b) the "trick" of using a bootable OS X installer on a USB drive to reinstall OS X if it goes bad on the internal drive?

    Also @chrfr, I realize that Mac mini will not boot 10.12, hence the extra step of upgrading it to 10.14 on the mini prior to trying to boot it.

    Thanks again.
    --- Post Merged, Feb 6, 2019 ---
    Actually, I just found this memo from Apple:

    Apparently you can disable the secure boot features if you so choose (at your own risk, I know). Does this change your response at all about whether my original plan is feasible? I'd like to a working system up as soon as possible, and then maybe after that I can slowly migrate to a more accepted install with System Migration and reenable secure boot. That memo also answers my question about booting off external media.

  5. chrfr macrumors 604

    Jul 11, 2009
    There is no way whatsoever to run 10.12 on the 2018 Mini. The oldest operating system that can be used on a given Mac is the earliest that particular model shipped with, and in this case, that's 10.14.
  6. macuser_123 thread starter macrumors newbie

    Mar 21, 2018
    Not trying to be hardheaded, I just want to make sure your answer applies to what I'm trying to do. I'm not trying to run 10.12 on the 2018 mini directly. I am going to create a new partition on the mini HD and clone the 10.12 system to that. Then bootup on the 10.14 partition that it comes with, then from within 10.14, run the 10.14 installer and update the OS on the 10.12 partition to 10.14, and then try to boot off that new 10.14 partition. Doesn't even need to be on a separate partition on the same drive. I could pull the hard drive from the iMac, put it in an enclosure and connect to the mini as an external drive, and then from within 10.14 on the mac mini try to upgrade the OS on the external drive to 10.14, and then clone that drive to the mini.

    If _that_ still won't work, how about updating the 10.12 drive to 10.14 using my MacBook Pro that supports both 10.12 and 10.14, and then cloning that 10.14 system to the mac mini? Would that work?

    And if _that_ still won't work, then I'll give up and do Migration Assistant.

  7. chrfr macrumors 604

    Jul 11, 2009
    Ok, that may work. I'd try Migration Assistant first, however. I think you'll be surprised at how well it works.
  8. macuser_123 thread starter macrumors newbie

    Mar 21, 2018
    Thanks. And I will go ahead and try Migration Assistant first per your advice.
  9. FNH15 macrumors 6502

    Apr 19, 2011
    You can also do this the opposite way. Boot your iMac into target disk mode, and download and open the Mojave installer on your Mac mini. Set the target disk to be the iMac's disk, and it will upgrade the OS on the iMac's drive to 10.14. You can then clone the drive to your Mac mini.
  10. Fishrrman macrumors P6


    Feb 20, 2009

    You're going about this all wrong.

    Here's what you need to do, and if you follow my instructions, I guarantee a 98% chance of success.

    1. You will need an external hard drive, and either CarbonCopyCloner or SuperDuper. Both of these apps are FREE to download and use for 30 days, so this will cost you nothing.

    2. When the new Mini comes, DON'T boot it right away.

    3. Just before you unpack the new Mini, do a full cloned backup on your OLD internal drive. Then, disconnect the backup drive.

    4. Now, set up the NEW Mini on the table. Connect the backup drive. OK, you're ready for the next step.

    5. Press the power on button on the NEW Mini for the first time. Let it boot to the setup assistant.

    6. Begin setup. At the appropriate moment, setup assistant will ask if you wish to migrate data from a previous computer or drive. YES, you want to do this, so...

    7. "Aim" setup assistant at the external cloned backup and give it a few minutes to "digest everything". BE PATIENT.

    8. Setup assistant will present you with a list of stuff to be migrated, including apps, accounts, data, and settings. I recommend that you just leave everything checked.

    9. Now turn setup assistant loose and "let 'er go to work". Again, BE PATIENT. It's going to take time to bring everything over. Maybe an hour, maybe more.

    10. When done, you will see a login screen on the new Mini looking for your password, so enter it.

    11. You should now see a desktop that looks pretty much like the other one looked.
    Take a few minutes, look around, check apps, etc.

    12. Disconnect the cloned backup, and you're done.
  11. macuser_123 thread starter macrumors newbie

    Mar 21, 2018
    Thanks Fishrrman. That's basically Migration Assistant, or whatever it is called now, which other people have suggested giving a try. My longstanding impression was that it would migrate a lot of things, but would leave a lot of things behind like icon position preferences, view preferences, and lots of little startup utilities I have in the /Library folder behind, which would be a pain to manually restore. But based on what you and others have said and further reading, it sounds like it is more comprehensive than I gave it credit for, so I'll give it a try. I won't even have to clone to an external disk; my old internal drive is a SSD I installed that I want to repurpose anyways, so I will just pull it out and stick it in an external enclosure and use that as the migration source.

    Thanks for taking the time to detail step-by-step.
  12. AnonMac50 macrumors 65816

    Mar 24, 2010
    One more way, you can clone your iMac’s drive to an external drive (I usually use Disk Utility or Terminal to clone), then plug it into the Mac mini. After that, you could install Mojave on your external drive (for example using internet recovery), then when it’s done, clone it to the internal drive of the mini. I haven’t tried this method myself, but I see no reason why it shouldn’t work.

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