hoakley June 4, 2021 Macs, Technology

How to make macOS betas and upgrades safer

With WWDC almost upon us, the imminent first beta-release of what’s expected to be macOS 12, and 11.5 also in beta, many are now wondering how best to install these, or even macOS 11.5 when it’s released. How should you prepare for the possibility that any of these could prove a lemon? How can you upgrade while retaining the ability to roll back to your current macOS?

The traditional trick of cloning your current internal storage to an external disk, so that you can clone it back if you need to roll back macOS, should still work on an Intel Mac, but is likely to fail on an M1 model, leaving it stuck and dysfunctional until Apple provides an update which isn’t so flawed. This article suggests some ways out.

Don’t install betas at all

The golden rule of beta-testing is that you should never even consider installing any beta-release on a production system, using only systems which you can afford to have fail. The snag at the moment is that many need to test on both Intel and M1 Macs, and relatively few have spare Macs covering both architectures. That may force you to compromise, which is what the rest of this article is about.

One important consideration before deciding to press ahead and upgrade an Intel Mac you can’t do without is firmware. Although you can roll back macOS, you can’t install older firmware. The only exception to this is for a Mac with a T2 chip: you can then use Apple Configurator 2 to update the firmware in the T2, and erase recoveryOS and macOS on the Mac’s internal storage. Before considering this, install Configurator 2 and study its Help book. You’ll need a Mac running macOS 10.15.6 or later, a USB-C to USB-C charge (not data) cable, and of course a second Mac.

Don’t install the upgrade on your internal disk

For M1 Macs in particular, this should be a good choice, and is how I do all my summer beta-testing each year. This still carries a risk, in that your Mac may install a flawed firmware update. You can reverse that if it has a T2 chip or an M1 SoC, as I mentioned above, but for a plain Intel Mac the only recovery would be a subsequent firmware update which could be tricky or even impossible to install. So there remains a small risk of disaster.

The procedure for installing macOS on an external disk attached to an M1 Mac runs:

Connect the disk to an available port on your M1 Mac, which could (subject to its compatibility) include a dock or hub.
Format the disk using Disk Utility. If it has been previously formatted using an older version of macOS, I recommend re-formatting it with 11.4 or later if possible. At this stage you can divide it into containers for multiple versions of macOS if you wish.
Run the full Installer app and select that external disk as the destination.
Towards the end of the installation process, the installer may claim there’s “about a minute remaining” for many minutes. Give it time!
Once installed, the Mac will start up in the newly installed macOS for you to configure it in the usual way.

As you’d then expect, you can switch between booting from the internal and external disks using the Startup Disk pane or in Recovery mode.

If you must install the upgrade on your internal disk

The best approach to work out what you need, is to consider how you’d recover your Mac in the event that the upgrade caused a serious problem.

For an Intel Mac, you need a bootable external disk containing your previous macOS, together with its data, which could if necessary be provided from a Time Machine backup, for instance. There is a twist here for Intel Macs with a T2 chip, though: you’ll need to enter Recovery Mode and ensure that Startup Security Utility is set to allow booting from external media, as Apple explains here. Without that, your Mac won’t be able to boot from the recovery disk which you’ve prepared for it.

Once your Intel Mac has started up from that external disk, you can then decide how best to return its internal disk to a stable state, which could include cloning the external disk back to internal storage, or installing a fresh copy of a more stable version of macOS and restoring/migrating from your backup.

For an M1 Mac, because it can always boot from a suitable external disk, you might think that all you need is a bootable external disk. While that might get your Mac up and running again, it can’t be cloned back to the internal disk, so complete recovery is going to be more complicated. In any case, that can’t restore a previous version of macOS to the internal storage, nor can it address any problems arising from a firmware upgrade – which may include its Recovery system.

The cleanest and quickest way to roll an M1 back to a previous macOS complete with its firmware is to perform a full restore using Apple Configurator 2. To do that, you’ll need another Mac running at least macOS 10.15.6, Apple Configurator 2 (free from the App Store), a USB-C to USB-C charge (not data) cable, and the restore image, an IPSW file of around 13 GB. Configurator can download the latest IPSW for you, or you can obtain that or older from Apple, via Mr Macintosh’s listing.

The procedure is detailed in Configurator’s Help book, and in this article. Once your M1 Mac has been successfully restored, you then configure it as if it was a new M1 Mac. That gives you the opportunity to migrate your data from your backup, or cloned Data volume.

It may instead be possible to simply install the current or previous release of macOS on your M1’s internal storage.

To re-install the current release, it’s simplest to enter Recovery mode and use the main Options menu. This may even preserve your existing Data volume in the new bootable volume group it creates. Otherwise you’ll need to migrate from your previous backup or clone. For an older release, you’ll need its full Installer app, but might find that can’t be installed on your internal SSD, in which case you’ll have to use Configurator to perform a restore from the appropriate IPSW file.

None of these solutions uses any clone or copy of the current System volume. Thus, there’s no point in trying to clone the System volume from your internal storage, as it’s simply a waste of space. Instead, ensure that you have at least two faithful copies or backups of the Data volume – something which is easy using Time Machine, Carbon Copy Cloner, and/or SuperDuper!

Whatever you do

Finally, whatever you decide to do, don’t make snap decisions to change your plan and end up putting your Mac at risk. Some betas don’t install reliably on certain media or configurations. If that prevents you from putting your plan to install that macOS on an external disk, don’t install it on your internal disk without making proper provision for any problems. The chances are the next beta will address those problems.

Never rush into testing any pre-release software. Think the consequences through carefully and protect your Mac from disaster.

27Comments

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1

Graham on June 4, 2021 at 7:00 am

What about installing the beta in a different volume on the internal disk?
https://support.apple.com/en-gb/HT208891

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  performa475 on June 4, 2021 at 7:49 am
  
  That advice applies to Intel Macs and needs updating to cover M1 machines.
  
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    Graham on June 4, 2021 at 8:56 am
    
    Out of curiosity, I just tried it. My main volume already had the beta on it. I followed the advice in the above article, installing from Recovery onto the new volume. It worked, but then when I attempted to revert to the first volume, I was rebooted into RecoveryOS and had to re-verify it.
    
    This kind of didn’t work a couple of times, I was taken to the Setup Assistant (where I got stuck because of some residual DEP setting although I had removed the computer from any PreStages), so it was apparently still booting to the new volume, but on the next attempt I was able to boot back into the first system.
    
    So, it doesn’t seem like a very robust method, but it kind of worked – I’ll do some more tests.
    
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    - 4
      
      hoakley on June 4, 2021 at 9:01 am
      
      You’re very welcome, but I hope that you’re well-practised at re-installing macOS, or even restoring in DFU mode. Because the chances are that sooner or later that’s what you’ll need to do.
      I make my recommendations clearly above.
      Howard.
      
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    - 5
      
      Graham on June 4, 2021 at 9:22 am
      
      Yes, of course, I’ve been testing Apple Silicon booting processes since receiving the DTK and my M1 remains a test device, so reinstalling by whatever means is well practiced.
      
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- 6
  
  hoakley on June 4, 2021 at 8:57 am
  
  Thank you.
  Please study the contents of that TN carefully. It refers to installing a beta of macOS Mojave, and is dated 2019.
  I strongly recommend that you don’t try that with betas of macOS 12 in 2021. Indeed, even Apple recommended using separate containers or disk for the first betas of macOS 11 a year ago.
  Howard.
  
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  - 7
    
    Graham on June 4, 2021 at 9:15 am
    
    Do you have a source for that? I’ve heard of using a different container, so I tried making a partition, but the option for creating a new partition was greyed out.
    
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      hoakley on June 4, 2021 at 9:52 am
      
      Apple’s release notes for the first beta of macOS 11 specifically recommended using separate containers not volumes.
      Trying to add containers to the internal SSD of an M1 Mac is also not a good idea. When it works, it can leave all sorts of strange problems.
      This article isn’t about what’s possible. I expect it may be possible to install betas of macOS 12 in volumes on the internal SSD. This is about what is wisest and best, and likely to cause you least trouble, particularly in the event that everything goes pear-shaped, which isn’t unlikely with betas.
      Howard.
      
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9

EcleX on June 4, 2021 at 7:18 am

It seems that the only safe option is not installing betas in the internal or external disks of production Macs, but installing on internal or external disks of a different Mac. The beta Mac.

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10

performa475 on June 4, 2021 at 7:34 am

Excellent advice. I’m still reading up on how to use Configurator 2! From previous bad experiences, beta versions of macOS are best run from an external drive!

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11

kapitainsky on June 4, 2021 at 9:06 am

And for many of us it is perfectly fine to test new macOS beta features in some virtual machine environment. And excellent VMware Fusion 12 has now free version. It yet has to be seen how well it will tackle macOS 12 (at least initially) but for 11.5 works perfectly.

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- 12
  
  hoakley on June 4, 2021 at 9:53 am
  
  Yes you can, although if you have problems in a VM you can never be sure whether it’s the beta or the VM, which can make them very frustrating. Each year I follow the struggles those who do this go through, and am happy not to try it.
  Howard.
  
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  - 13
    
    Graham on June 4, 2021 at 9:55 am
    
    Also, you cannot currently run a macOS VM on an Apple Silicon Mac, so you are restricting yourself to Intel at this point.
    
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      hoakley on June 4, 2021 at 11:25 am
      
      Thank you – yes, an important reminder, so I checked their status.
      Parallels is aiming to get Big Sur virtualised on M1 Macs over the summer, so might be able to run macOS 12 too. It does run native on M1 Macs, and already offers Windows for ARM and several Linux distros.
      VMWare doesn’t yet run native on ARM, although they’re working on it. They say that they have no plans to virtualise macOS on M1 Macs, though, so I think that can only be a long-term hope.
      So for macOS 12 on ARM, the only choice at present is to run it for real, and not virtualised.
      Howard.
      
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  kapitainsky on June 4, 2021 at 10:40 am
  
  Yes this is not perfect method but can be extremely practical in e.g. software testing in future macOS versions. It is quite mature on Intel platform but indeed virtualization on ARM is still in infancy – both key vendors VMware and Parallels are still working on it.
  
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16

winmaciek on June 4, 2021 at 10:14 am

Personally, I would also avoid signing in with an iCloud account, especially with early releases. Particularly if one uses it to store photo library or somewhat important data. There’s always higher chance of an early beta release messing something up. And because of the nature of the iCloud these errors are likely to propagate among all devices. In case of cloud storage it may be significantly more difficult to do any sort of recovery.

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  hoakley on June 4, 2021 at 11:28 am
  
  Yes, that’s generally good advice. If I recall correctly either Mojave or Catalina betas made a real mess of many iCloud accounts.
  The snag is that many testing their own software much test against iCloud. You could create a separate iCloud account to do that, or ensure that you don’t rely on iCloud too much (which might be good advice anyway!).
  Howard.
  
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18

Simon on June 4, 2021 at 3:20 pm

The bottom line seems to be that you just shouldn’t test a new macOS (beta or release) on a production system. That’s fine. And if you’re a dev who simply needs to see that your app runs ok that’s probably cool too.

The problem I see is rather for more ‘regular’ users who want to see if they like the new macOS and what it brings or if they prefer to stick with what they have. The only real way to test that properly is to run your daily workflow on it and see how that gets impacted/improved. It’s hard to mimic your real digital life on a spare system. I’d like to think you can still do that with a clone prepared in advance and if things go sideways you clone back. On M1 that could mean nuke (after cloning to preserve any data changes you’d consider permanent), set up from scratch, and then use MA to get data back from your clone.

But what’s still not quite clear to me is if firmware can become a problem in that scenario. Sure, there’s always Configurator if you have another Mac available and the right type of USB cable (what’s with this silliness about a specific type of USB cable anyway?), but that seems far more involved than just running installer from Recovery and finishing with MA. But perhaps I’m getting it backwards, and the M1 crowd is actually better off than those of us with T2s. ???

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  hoakley on June 4, 2021 at 10:46 pm
  
  With an M1 Mac, you can do either: to revert the system alone, simply install the current version of macOS from Recovery mode. If possible, that will hook up with the existing Data volume and you don’t then need to migrate. The option that Intel Macs lack is the ability to revert the firmware too, something which is quick and easy on an M1 Mac. Mr Macintosh now offers information which allows T2 Macs to be reverted to an older version of the iBridge (T2) firmware, but that doesn’t work for plain Intel Macs.
  I have two T2 Macs (iMac Pro and MBP), and two M1 Macs (mini and MBP). I’de far sooner work with Recovery etc. on the M1 systems – it really is that simple, provided that you have another Mac to run Configurator.
  I don’t know why Configurator requires a USB-C charging cable, but that also applies to T2 Macs.
  Howard.
  
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20

Barry Sharp on June 4, 2021 at 6:10 pm

Thanks Howard…

You of course give very good advice for the safe and trouble free beta testing process.

For me, and my M1 mini, unless I can nail down a sure way to maintain Reduced Security along with having 3rd party extensions load and stick for the external bootable beta device (and especially maintaining these two things on my internal macOS while booting up/down on the external), I cannot entertain using an external for Big Sur testing.

At this time, what I find works without any real fuss and bother is to have Production Big Sur and a Big Sur Beta system co-locate on my internal SSD within the same Container. That is, within the same Container having Production Big Sur OS+Data volume set alongside Test Big Sur OS+Data volume set. At this time for example I have Big Sur 11.4 in one volume set and Big Sur 11.5 in the other. This setup works seamlessly, reliably, and is super quick being able to switch between the two systems.

I’d love to use an external device for testing, but as mentioned above, I cannot safely do this and when I try using an external I encounter issues I cannot live with.

The real killer here, is managing and maintaining my needed 3rd party extensions as I run Production and Beta testing. From my research and with contacts at two of my 3rd parties that provide me with their Universal kexts to extend the kernel, I’m hearing/understanding they will not be releasing their extensions using Apple new ‘driver kit’ for at least a year (this is for Promise and SoftRAID extensions). I’m told Apple is already one year behind delivering a reliable ‘driver kit’.

Thanks again for posting your articles. They are very informative. Maybe you can issue one related to the issues surrounding 3rd party kernel extensions for the Apple Silicon Macs.

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  Barry Sharp on June 4, 2021 at 6:32 pm
  
  Of course, one way to remove the issues related to maintaining Reduced Security for my bootable devices, and to avoid the issues related to successfully and reliably loading and maintaining my needed kernel extensions, is for me to abandon the need for the kernel extensions. This would require me to trash/sell most of my external storage devices and replace them with units not requiring kernel extensions. At this time this is a serious option I’m considering for the long term. I’m not happy with the thought of having to wait a year or so for my 3rd parties to develop/test/implement and release their reliable well tested alternative software drivers for Apple Silicon’s Big Sur and beyond.
  
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  - 22
    
    hoakley on June 4, 2021 at 10:50 pm
    
    Thank you.
    I do understand – I was nearly caught in the same situation with my Promise Pegasus RAID. They’re quite expensive, and built to last for many years, but like so many other excellent hardware systems, the software support isn’t as durable. Ironically, I replaced mine with an OWC ThunderBay, which I had also intended to operate in RAID. When I discovered that SoftRAID was dependent on another unreliable extension I abandoned that idea and have since used the drive as JBOD. I had to completely redesign my backup strategy, but now have no dependence of wobbly or unmaintained extensions. Not as elegant, perhaps, but more robust in the long run.
    Howard.
    
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- 23
  
  hoakley on June 4, 2021 at 10:46 pm
  
  Thank you.
  Howard.
  
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24

Barry Sharp on June 4, 2021 at 10:05 pm

What about this advice from Apple https://support.apple.com/en-gb/HT208891…. but does not explicitly mention Apple Silicon Macs.

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  hoakley on June 4, 2021 at 10:57 pm
  
  Thank you.
  That’s the same article, dated 31 January 2019, using macOS 10.14 beta as an example.
  Howard.
  
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26

Gabester on June 7, 2021 at 4:34 pm

I don’t have an M1 Mac to test on, and haven’t the courage to try it on one of my few Intel Macs yet, but isn’t the point of APFS that we ought to be able to take a snapshot of the disk manually and then roll back if the update or upgrade or beta … doesn’t work as anticipated? Mind you I don’t really comprehend what Apple’s done in Catalina and Big Sur with containers vs volumes, so maybe that thwarts the use of snapshots?

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  hoakley on June 7, 2021 at 8:57 pm
  
  Thank you.
  Snapshots could work well, but in Catalina the System volume is read-only, and in Big Sur you don’t even run macOS from the System volume, but from a snapshot of it, all carefully sealed with cryptographic hashes. AFAIK you can’t take a snapshot of a snapshot.
  You can certainly take snapshots of the Data volume, which Time Machine does anyway, but they don’t contain the System, so aren’t bootable.
  Life should be so simple!
  Howard.
  
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