I want to migrate all data from my existing 2015 MBP that runs on Big Sur to the latest 2021 MBP with M1 Pro chip.

I want to be able to transfer all files and all settings to the new MBP and this includes the hidden .ssh folders, /etc/hosts files, to name a few.

I have read about Migration Assistant being able to do this over Wifi but quite unsure if all the data & apps will get transferred or not OR if it cause issues because the OS versions will be different.

Can I use CarbonCopyCloner and "clone" my old OS + data on the new M1 MBP which runs on a new version of MacOS? Which OS would be present after cloning? Would the new OS cause issues especially since I am on an Intel MBP.

I will have only a weekend to complete this process before I have to ship my old MBP so looking for best practices from people who have completed this process before.

Basically want an exact copy of what I currently have in my 2015 MBP to avoid any troubles with office work.

  • Your last sentence is a problem. You don’t want an exact copy since that causes troubles and issues. Any cloud sync, volume identity records, corruption and irrelevant log files and caches cause headaches more than a clean install and data migration. Clones are ok for bootable backups - do you have any backup on the old Mac? That is far more important to help you with the transition to M1 imo
    – bmike
    Commented May 25, 2022 at 10:41

4 Answers 4


I would recommend against cloning your old disk to boot from it, it may very well not work. But Migration Assistant is the way to go, it's acually quite capable to copy both your data and any applications over. Apple has a support document describing the details.

So what I would do in your case:

  • get an external SSD (USB disk) and clone your old MBP disk onto this with CCC. This will then be your backup disk in case the migration partially fails but you still need to give the old MBP back
  • run Migration Assistant to copy everything over the new MBP. Depending on the amount of data you have this may take a while over WiFi
  • install Rosetta 2 on the new MBP (because at least some of the applications you copied over may still be using Intel code)
  • upgrade Applications to their newest version if possible
  • Migration assistant is always my first choice. Connect Thunderbolt cable or USB data cable or Ethernet cable direct for very fast speeds. Then clean up any files that might be missing or make a time machine backup of the old Mac just in case before wiping it.
    – bmike
    Commented May 24, 2022 at 21:22

Trust me - Migration assistant is the way to go. I've made countless transitions (I use my Time Machine Backup to restore the data), and you just migrate, set your account's password, enter your apple password, and boom, your mac is just like before. I will say that there is one caveat: the apps lose their permissions. For example, if you use screen sharing on zoom, you will have to re-allow zoom to screen share. But other than that, it's as seamless as it can be. I've dealt with all this cloning disks stuff in the past, and i've really regretted just not using migration assistant. Trust me, with apple today, you do NOT need to clone stuff like how you do in windows for a seamless transition.

Tl;dr: just use migration assistant. Either use an ethernet/usb cable between the macs or restore using a time machine backups.


Can I use CarbonCopyCloner and "clone" my old OS + data?

Now that the OS is on a separate, sealed, read-only volume, there is absolutely no need to clone the OS from your old Mac. I certainly wouldn't 'down-grade' the OS from the factory install, either, even if possible.

Cloning the "Macintosh HD (Data)" volume is an option, but I'd caution that going from an old Intel Mac to an M1, there may be differences in configuration files. I cloned my 2012 Mini to a T2-chip 2018 Mini, and that didn't work without reinstalling the OS, and sorting out authorisation keys or something.


To the caveat that anonymous mentioned, above, I would add that Migration Assistant is known to blow away all the original timestamps on your files, and reset them to the time that you migrated.

If you, like many people, want to sort your files in the order they were created, Migration Assistant may disappoint you, or, worse, it may make a total mess of your Documents and Downloads folders.

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