This has changed greatly over the last few versions of macOS, and differs between different types of Mac. Here’s an outline.
Startup Disk
When a startup disk is running short of space, needs a good clean up, or isn’t quite right, it’s tempting to try surgery. Here’s what you can get away with.
Monterey changes the way that Recovery works on M1 Macs, making them more like Intel Macs by using a paired Recovery volume. But that could spell trouble.
Creating the external bootable SSD, downgrading security and allowing kexts, then trying to install a kext on an external drive which must be ejected.
Assigning ownership to an external bootable disk doesn’t always work in Recovery mode on an M1 Mac. But there’s an easy workaround.
M1 Macs are different, as they always start booting from their internal SSD. Basic configurations are simple, reliable with well-established disaster recovery methods.
Full macOS installers come in different presentations according to how they’re obtained. Explained here are what’s in an installer app, and how a bootable installer disk works.
One command in Terminal which instantly disables any support, and why you can’t (yet) boot your M1 Mac in Linux.
My M1 Mac mini was stuck trying to start up. Its power light was on, but there was no video output, and to all intents it was dead.
How boot security has changed in the M1 Mac. What it allows you to do, and how it restores flexibility and versatility of external boot disks.
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