Which versions of macOS can you ‘dual boot’, should you install them all on the internal SSD, or is a bootable external disk better, and when would you need to virtualise?
dual-boot
What if you want to boot your Mac using two or more different versions of macOS, with different versions of APFS? Here’s how to avoid problems.
A popular insurance when upgrading to a new version of macOS: how to keep your Mac running both Monterey and Ventura. Covers all models including M-series.
Installing two different versions of macOS within a single container brings flexibility as they share free space, a little economy maybe, and complexity – explained here.
macOS 11.4 brought major changes to the way M1 Macs handle external bootable disks. This explains how this works during the boot process.
macOS 11.4 has finally fixed all the problems with installing current and older macOS on external disks, and booting an M1 Mac from them.
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.
How an M1 Mac can start up from an external bootable disk, and how that can fail. All about boot security policy, and how that’s applied.
How changing a volume’s boot policy can let you boot in older macOS, and update, if you wish. For anyone who uses external bootable disks with an M1 Mac.
It’s got to be better than Catalina, so why not upgrade when it first comes out? Here are some suggestions to help you make your decision.
The Eclectic Light Company 