What is the best way of migrating my data from an old intel Mojave MBP to a new Monterey M1 MBP?

I will soon have to migrate an old (10+ years) MBP running Mojave (the latest and greatest OS it can run) to a new Monterey M1 MBP. I assume that reinstating the old Mac to the new one using Migration Assistant and time machine might not work that well, since the two OSs are so far apart (basically, I assume that a lot of the stuff in ~/Library and /Library might not be organised in the same way in the two OSs (I did have some issues with Mail.app after migration with MA and TM between two Macs with a different OS version). I might be wrong about my concerns, but if anyone has a best practice to migrate from a very old to a very new Mac I'd be much obliged.

3 Answers 3


I'd use a 'live' Migration rather than one from Time Machine.

I have much anecdotal evidence to support this bias, but no citable source. I've never had a direct Mac to Mac Migrate fail, even from an old to new OS. I've even successfully Migrated Windows users to new Macs by this method.

As you set up the new Mac, Migrate before you configure any new accounts, otherwise you end up with two identities/accounts & will have to unpick it manually afterwards.
When presented with the Migration option, you can select another Mac on the same network. Go to the old Mac & launch Migration Assistant (Applications/Utilities) to make it available as a source for the new Mac. I can't test this right now as running it will quit everything on the source Mac in preparation - but you get the opportunity to enter a confirmation code on both Macs to ensure you're Migrating the correct one & have the authority to do so.

Migrating in this way should convert things like Mail databases to the new format. It should also move anything that cannot run on the new Mac to appropriate folders placed on the new Desktop, so you can sort through & see which apps etc you need to update/replace.

  • Can I use a cable between the two macs directly for this? I imagine it would be much much faster than using the WiFi. Commented Mar 28, 2022 at 9:20
  • 2
    I think theoretically you can use Thunderbolt, though Apple doesn't mention it on their own site, there are examples of it working on YouTube [which would worry me a bit… do you want a speedy hack or a safe, trusted method?] I've never tried it. I've always used hard-wired ethernet.
    – Tetsujin
    Commented Mar 28, 2022 at 9:36
  • I had good experiences with Migration Assistant using both Ethernet-based migrations as well es restoring from an external drive with a full backup of the old Mac.
    – nohillside
    Commented Mar 28, 2022 at 11:10
  • I've had Time Machine fail me in so many different ways I no longer trust it at all, even for the simplest file recovery task. From Migration fail to drive corruption to refusal to restore any file none of which have ever really been adequately resolved; workarounds were found, but no fixes at all.
    – Tetsujin
    Commented Mar 28, 2022 at 11:20
  • @Tetsujin Apple mentions here that using Migration Assistant with two Mac's connected over Thunderbolt is supported (I used this method when moving from an Intel MBP to an M1 Mac Mini).
    – robertklep
    Commented Mar 28, 2022 at 18:10

My experience is similar to Tetsujin's: I've had good results using Migration Assistant over several upgrades, including most recently from Mojave/Intel→Monterey/M1.

I did some preparation before-hand, which was mainly replacing all my old 32-bit apps with Universal (Intel+ARM) versions where available, or at least 64-bit Intel versions. I found a free app called Go64 which did a great job of identifying 32-bit apps and helping keep track of which ones I hadn't upgraded yet. (The easiest cases were apps with free upgrades available; some cost money; and others haven't been updated and so I needed to find alternatives.) It can also help with upgrading x86-64 to ARM, though I think that won't be critical for a couple more versions.

I ran Migration Assistant as part of the initial new-user set-up on the new machine, but it got stuck at ‘Starting up…’, after scanning and letting me choose which categories to copy, but before actually copying anything. (I tried both over wifi, and by connecting the Time Machine drive directly via USB, but neither worked.) I worked around this by skipping the migration, completing the rest of the initial set-up, getting to the desktop, and then running /Applications/Utilities/Migration Assistant manually, which worked fine.

I was discovering oddities and omissions for a few weeks after the migration — though I guess I'm a ‘power user’, and most Mac users probably wouldn't hit them. I'll go through some of them here, just in case.

One potential issue is that the root directory / is no longer writeable on Mojave (not even by root). I learned this the hard way (when some directories I'd put there seemed to disappear in the migration). If you've added any top-level files or folders, I'd suggest moving them into your home directory (probably /Users/<username>) before migrating.

I had to manually install Rosetta and the command-line tools. (Obviously, only if you're going to use them.)

My user account is not an admin (for security reasons; I have a separate admin account to use when needed), but after migration I couldn't remove admin rights. I eventually did it with sudo dseditgroup -o edit -d <user> -t user admin.

Obviously you'll need to check over your network/wifi/Bluetooth settings. It remembered most of mine, but forgot my DNS setting, and re-enabled Bluetooth. (It seems to do the same after every update, too.)

Starting a new Terminal window showed the error /etc/zshrc_Apple_Terminal:14: INSIDE_EMACS: parameter not set. I had to change $INSIDE_EMACS to ${INSIDE_EMACS-} in that file. (And then redo that after the first update…)

If you use iStat Menus, make sure you're running the latest version. When I migrated, the current version lost access to most of the MBP's sensors, showing only the SSD temperature. v6.61 fixes that. You may need to give it Full Disk Access in System Preferences too. (In fact, you'll probably need to give quite a few programs Full Disk Access; it doesn't seem to migrate that very well.)

All the programs I'd installed via Homebrew still worked, surprisingly enough. (Rosetta works very well!) However, it stuck to the x64 versions of apps. To use ARM versions, you pretty much need to reinstall Homebrew from scratch: the ARM version uses a completely different location (/opt/homebrew/ instead of /usr/local). Run brew leaves before updating to show which packages you need to reinstall, and make sure you update $PATH etc.

If you use the same Time Machine drive, it will probably start a new backup set for the new machine. (This is probably a good thing.)

iTunes has been replaced by Music, which does most of the same things (though IMHO often not as well). It successfully migrated all my tracks and playlists; but it lost the view settings, so you may need to set up your views, columns, &c again. If you use iTunes Volume Control, that still works with Music, though you may need to reinstall it. Podcasts have been separated out to a new Podcasts app, which should remember your subscriptions (though again, I don't think it works as well).

A few command-line programs need different options in Monterey. For example, awk no longer has a --lint option, and scp now needs -T. And some programs such as emacs and svn are no longer included, so if you use those you'll need to get them from Homebrew or similar.

It recognised my USB-to-serial adapter (without needing any driver installed) — though its device name (in /dev) changed, so I needed to tweak some config for that.

If you have any Perl modules, you might need to reinstall those.

It didn't copy my sudoers file.

If you use at/batch, you may need to give /usr/libexec/atrun Full Disk Access in System Preferences.

For some reason, all my Chrome extensions (uBlock Origin, &c) vanished, and I had to reinstall them.

And even more bizarrely, the Times font vanished! But I managed to find a replacement and installed that.

But almost everything else Just Worked™, and the migration went more smoothly than I feared. Rosetta in particular is very good indeed — running x86 code on ARM totally transparently (except for the very first launch of each app failing). The most time-consuming and painful part was upgrading or replacing all my old 32-bit apps, but as mentioned, I'd been slowly going through all that in the months before the migration.


Ok, I did find the fastest way -- which is by creating a Thunderbolt bridge and then using Migration Assistant. I followed these instructions, and I followed them. When I opened Migration Assistant in the two Macs the Thunderbolt bridge was the connection used, and the speed transfer was 10x faster than WiFi at least (100Mb/s vs not even 10Mb/s).

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