Mike has posted a very important post on the Carbon Copy Cloner / Bombich Software blog:
Beyond Bootable Backups: Adapting recovery strategies for an evolving platform. I recommend reading the whole thing, but some important pieces (Note: the italics only emphasis is original but the bold and italics emphasis was added by me.)
Back in December I had a conference call with Apple …. They indicated that they were working to resolve the ASR/Apple Fabric issue, but they made it very clear that copying macOS system files was not something that would be supportable in the future. Many of us in the Mac community could see that this was the direction Apple was moving, and now we finally have confirmation.
What does all of that mean? In theory it means that Apple Silicon Macs cannot boot at all if the internal storage fails. Lacking a Mac whose internal storage I was willing to damage to prove this, I contacted the authoritative experts within Apple in April and they unambiguously confirmed that that is the actual result – you can’t boot an Apple Silicon Mac if the internal storage has died.
All of which leads me to conclude the bootable backups are no longer going to be a part of my backup routine.
As someone who has prided himself on his comprehensive backup system, it pains me a bit to give up something I considered to be one of the main pillars of that system, but if I can’t boot a “dead” Mac from a bootable backup anyway, there’s no real point in having one.
However, I think this news has to be worst for people with only one Mac. Previously I would have had a bootable backup drive in case I woke up one morning and my Mac wouldn’t boot. If that happens now, I could use one of my older Macs to get by. But if you aren’t able to have an entirely separate computer… that’s a scary thought.
Back in February, Adam Engst wrote The Role of Bootable Duplicates in a Modern Backup Strategy at TidBITS which I also recommend, and he concluded with this:
…I’ll stick with my nightly duplicates because they’re just too useful for troubleshooting and recovery. But I can’t say that bootable duplicates are the necessity they once were.
Adam is smart, experienced, and insightful. At the time I first read that article, I wondered if it was trying to convince himself (and others) of the seemingly inevitable, that is, to convince himself he didn’t need bootable backups because Apple was basically taking them away anyway. But, re-reading the article now, alongside the CCC blog post, I see that Adam was saying then many of the same things Mike is saying now.
I’m no slouch, but Mike and Adam are both smarter than me. I will be taking their advice.