My Mac Backup Strategy, was:
Having an external bootable backup meant that if my internal drive(s) failed, I could quickly fire up a workable system and continue working, until I restored it all to a replacement drive. But as I discovered last night…
At this writing, you can’t make a bootable backup disk with Big Sur. And the M1 (non-Intel) Macs can’t boot from an external drive. Now what? You could (and should) keep using Time Machine of course, but that is just saving your data and apps, not creating a “boot disk”. You’ll have to repair/replace your drive or Mac first, then recover using Time Machine. Unless you have a backup computer and work with all your data “in the cloud”, hours or days of downtime is inevitable with a hardware failure.
Short version: Make multiple backups of everything that is important to you. Including backing up to (a non-bootable) external drive with SuperDuper or other “cloning” utility. If your recovery strategy is “Make an appointment at the Genius Bar”, make sure you allow for at least a few days of downtime. If your business can’t afford downtime, try to work with all your data “in the cloud”, have a spare Mac, and be sure if you shut one Mac down, you can still do everything you need to on the other. And Test and Verify that this actually works!!
Readable Technical details and workaround(s) at Shirt Pocket Watch (SuperDuper developer’s blog) www.shirt-pocket.com/blog/, and this thorough summary from TidBITS: The Role of Bootable Duplicates in a Modern Backup Strategy.
— Read on
P.S. TechWite is also back from the dead. At least for this one entry. I’ve always been UNPREDICTABLE. 😎