Migration from iMac Catalina (Intel) to iMac Big Sur (M1)

[pine man]

I'm shortly to take delivery of an M1 iMac and I'm getting everything ready for the transfer/migration.

I use CCC and Time Machine on my existing iMac and shortly after ordering the M1 I found that CCC is about as much use as a 'chocolate tea pot' with the new M1! Probably an exaggeration but there does appear to be some shortcomings with it.

Anyway, given that I will have a full, up to date, CCC clone of my existing iMac as well as Time Machine, I'm wondering about the best way to get all my stuff from one device to another, bearing in mind the different OS and the new M1 chip.

Documents are no problem but what about all the software and associated files?

Is it better to install all the software from scratch?

Has anybody had experience of using CCC on the new M1 iMacs? I've read just about everything that CCC has published and now I'm thoroughly confused.

I'd be grateful for any advice - apart from cancelling the order!

 

[chscag]

Prior to creating a user account on your new M1 iMac, I recommend using the Migration Assistant with your latest Time Machine backup as the source. That should transfer everything over without causing any interruptions with data or software.

And you're quite right concerning CCC. Probably a good idea to read through the CCC blog on their web site regarding cloning and backing up with the new M1 architecture.

 

[pine man]

Great - Migration Assistant it is then.

I'll have another read of CCC but it seems as if you can only really back up the Data and not the System and any back ups cannot be bootable at the moment but things might change.

Thanks for your response.

 

[MacInWin]

@pine man I have done a lot of research and from what I can tell, the situation is not as dire as you might think. Basically, on the M1 systems the system files are locked in a secure portion of the System-on-a-Chip (SoC) that is encrypted and only accessible to Apple processes. On boot, the operating files are copied to a separate memory area that then acts like the boot drive we are used to seeing. Even the copies are then encrypted and for the most part write-protected, for security. So when a cloner comes along and wants to clone the System "drive" all it can see is the copies, not the originals, and it can't copy them in a way that would boot because of the boot sequence (copy, etc.) But cloners can, and do, very successfully copy the Data Volume just fine.

While that sounds bad for cloners, the same is also true of Time Machine. In the M1 systems, TM also does not backup the system files for the very same reason--they are recreated at boot by the boot process.

So, what to do? Just what you are doing now. If you have a cloner, you can continue to use it, and if you are using TM you can continue to use it.

But what if the "drive" fails and you need to "restore" the system? In the old days, you could boot from the external clone, then order a replacement drive (If it was replaceable) and when it came in you would swap it in, then clone from the external to the new internal and be on your way. Or you could just continue to boot from the external drive, even if the internal was not replaceable.

But in the M1, there is no "drive" to replace. The SoC has memory, some of which is used as a "drive," all tightly integrated. As a result of the design, if the problem is the "drive" has a hardware failure, your system is toast. There is no replacement, except to replace the entire logic board. And you cannot boot from an external if the internal is broken because the boot looks for the boot process on the internal storage only, even if you can designate an external as the boot device. If that boot process isn't there, it won't boot, period.

But if the issue is a software problem on the system drives, you can do a "restore" of the drive, "reinstall" the OS and then restore from the backup. The "reinstall" is not really a reinstall as you would classically think, but it is a recreation the system files as they would be copied over in the first step of the boot process on a new machine. Essentially the result is the same, you have a brand-new, virgin, copy of the OS, to which you can restore with Migration Assistant from either your cloned data or TM backup.

So, while a clone is no longer "bootable" as we used to think of it, it is definitely more useful than a chocolate tea pot!

 

[pine man]

Jake

Thanks ever so much for your explanation. It makes things an awful lot clearer. I suppose we (me) get stuck in our ways and get used to the way things have worked for such a long time. As you advise, I will continue to use TM and CCC and adopt the new way of working with them.

I accept that my reference to 'chocolate tea pots' was somewhat disingenuous and thank you once again for your help.

 

[MacInWin]

Peter, don't worry about it. I've heard the expression before, love the imagery! Not disingenuous at all, just colorful.

 

[Lifeisabeach]

Great - Migration Assistant it is then.

I'll have another read of CCC but it seems as if you can only really back up the Data and not the System and any back ups cannot be bootable at the moment but things might change.

Thanks for your response.

That’s not all exactly right. You absolutely can make bootable backups, but with the one I made a week ago, I had to do a clean clone. You can’t boot from an incremental backup. At least not if macOS has been updated on the internal drive. But a fresh clone absolutely will be bootable. It was previously believed that a Thunderbolt drive would be required, but I can vouch for USB-C being bootable. At least mine is.

 

[MacInWin]

@Lifeisabeach His machine is a new one, using the M1 System on a chip. Backups from those systems are ONLY bootable if the System drive is still fully functional. If the storage in the SoC has failed, the machine will not boot, period. There are also some complications from the way Apple has implemented the "1 True Recovery" process on the M1 machines. That said, it is possible to install BS on an external drive (not clone) and then boot to the Recovery process and set that external as the boot drive to boot from it, but if the storage holding the boot process on the SoC fails, that won't work. The same is true for the MBA you have. This article talks about the process in the context of the coming Monterey system, but does describe the boot process in place now as well. How Monterey changes Apple Silicon Recovery There are more articles on the changes to the boot process at that site as well.

Bottom line: Clones on Mx machines are possible, but not as useful as they used to be on the Intel systems.

 

[Lifeisabeach]

@Lifeisabeach His machine is a new one, using the M1 System on a chip. Backups from those systems are ONLY bootable if the System drive is still fully functional. If the storage in the SoC has failed, the machine will not boot, period. There are also some complications from the way Apple has implemented the "1 True Recovery" process on the M1 machines. That said, it is possible to install BS on an external drive (not clone) and then boot to the Recovery process and set that external as the boot drive to boot from it, but if the storage holding the boot process on the SoC fails, that won't work. The same is true for the MBA you have. This article talks about the process in the context of the coming Monterey system, but does describe the boot process in place now as well. How Monterey changes Apple Silicon Recovery There are more articles on the changes to the boot process at that site as well.

Bottom line: Clones on Mx machines are possible, but not as useful as they used to be on the Intel systems.

I know. I was addressing his concern that bootable backups were no longer possible.

EDIT: Allow me to point out the scenario I faced that led me to make my latest backup. I had installed USB Overdrive on my M1 MBA in an attempt to customize the buttons of a gamepad for use with a couple games that didn't have native gamepad support. Well it didn't do the job I needed it to do, so I deleted it. But I started having issues with the cursor moving around and activating the Dock on the side while in a full screen game, which should not have been happening. I dug around and found a .dext file installed by USB-O in /Library that I figured was the culprit. But i had no way to delete it. Not using the Terminal and sudo rm -rf. Not by enabling and logging in as root. Nothing worked. Nothing. I had to boot off of my external backup in order to delete that file from the internal drive. And yes, that fixed the problem.

 

[harryb2448]

Just run your CCC backup using Migration Assistant. Did the same with my SuperDuper clone of Catalina on the M1 iMac running Big Sur 11.5.2 when it arrived. Everything worked a treat.

 

[pine man]

There seems to be all sorts of 'possibilities' here but for the time being I will prepare for a Migration using Time Machine. Following that I will keep Time Machine going and do some trials with CCC and see what happens.

Thanks ever so much for all the interest shown, it's much appreciated and I will report back once I've got the M1 up and running.

 

[MacInWin]

I had to boot off of my external backup in order to delete that file from the internal drive.

In that situation it is possible to boot from external because the boot process on the internal was still functioning. And you could, I think, have achieved the same result by booting into Safe Mode. I don't know for sure that last one, but I suspect the file was being loaded at boot, which is why you couldn't delete it. But Safe Mode does not allow loading for non-Apple products, so that should have allowed you to delete it.

What is going to be interesting in the future is the challenge of running more than one version of macOS on the Mx systems. There is a new concept called "Owner" for the system that is not much publicized at this point, but which gets involved in the boot process even before any system is booted. And the assignment of "Owner" of the system gets entangled in the version the "Owner" can boot. So, for example, the system has to go through a lot of electronic gymnastics to allow you to boot the Monterey beta from an external drive when you have Big Sur installed on the internal. What is not clear at this point is how well that same set of gymnastics will be accomplished if the internal drive is running Monterey and the external is on Big Sur. I'm hoping some beta tester is working that way and that "it just works."

 

[pine man]

I suppose I should have checked but (un)surprisingly none of the devices plugged into the back of my 7 year old iMac will plug into the back of the new M1 iMac, when it arrives, without new cables or adaptors, apart from the ethernet cable. Surprising how the initial cost of the (reasonably priced) Mac is rising!

 

[harryb2448]

Peter it is called progress.

 

[pm-r]

none of the devices plugged into the back of my 7 year old iMac will plug into the back of the new M1 iMac, when it arrives, without new cables or adaptors, apart from the ethernet cable.

Would something like this help improve your connection/devices issue better than a bunch of new cables and/or adapters...???

USB-C Clamp Hub for 24-inch iMac | Satechi - Apple and PC Accessories

satechi.net

- Patrick
=======

 

[pine man]

I had a look and it is available from Amazon in the UK for £49.99.

The cables I need would cost £46.49 but that would not give me SD Card capability so the Hub could be the answer.

Many thanks for taking the time to find the info for me.

Edit - Uh oh! No Thunderbolt capability so I think I'll order the cables for now.

 

[pm-r]

Edit - Uh oh! No Thunderbolt capability so I think I'll order the cables for now.

I just mentioned that unit after doing a very quick search as a suggestion, with a bit of modification to the search phrase you would have found there are other suggestions that also provide Thunderbolt and maybe other ports.

Try this:
Search Page

And try a search on other brands as well. Lots of variation variables out there...


- Patrick
=======

 

[pine man]

Thanks Patrick

I decided to order the cables I originally identified, which will cater for all my Thunderbolt/USB4 and USB3 needs, and will leave the need for SD Card connection as it is something I only use about once a year for updating my cars SatNav.

I will be able to update the SatNav card on the old iMac as it will continue being used by my wife. Her PC is getting on a bit so I had this wonderful idea that she could have my old iMac and I could have a new one

 

[pm-r]

Her PC is getting on a bit so I had this wonderful idea that she could have my old iMac and I could have a new one

Aren't you lucky that she actually allowed you to use the new one?



- Patrick
=======

 

[Lifeisabeach]

In that situation it is possible to boot from external because the boot process on the internal was still functioning. And you could, I think, have achieved the same result by booting into Safe Mode. I don't know for sure that last one, but I suspect the file was being loaded at boot, which is why you couldn't delete it. But Safe Mode does not allow loading for non-Apple products, so that should have allowed you to delete it.

It didn't occur to me to try Safe Mode. Being a glutton for pain, I re-installed USB Overdrive. Oddly, I didn't get a .dext file this time. I tried SteerMouse, which I had also tried previously, and that didn't give me one either. I wound up installing an older version of USB-O which wasn't compatible with Big Sur. The install failed, but a .kext file did get placed in /Library. And I couldn't delete it. It was left behind despite using USB-O's built-in uninstaller option. Safe Mode didn't give me the ability to delete it. Nothing. I'll have to do it from my backup. So yes, bootable backups are possible AND have value.