Don’t just hold Command-R and hope that you’ll install the right version of macOS. Here’s structured decision-making to save you time.
startup
Single-user mode to run fsck to check and repair your boot disk became tricky with Fusion Drives. With a T2 chip, it’s not practical in its traditional form.
Extensive listing of places to find key information such as your User UUID/GUID, Ethernet MAC, model identifier, and much more.
What are the benefits to leaving your Mac running all the time? And the costs? Which should you choose to do?
A new version of Mojave brings some fixes, and introduces some new bugs. Here a few for starters. I’ll add more as we discover them.
Stepping through key points in the log as Mojave 10.14 starts up. Most of the key waypoints are similar to those in High Sierra.
Mojave’s first full release is looking relatively free of bugs so far. This list is updated as and when new information arrives.
What to do when your Mac won’t boot into the Desktop and Finder – another summary diagram for diagnosis and suggested solutions.
Adds details of the sequence of screens displayed at each stage, to help diagnose boot problems.
You want to boot your Mac from an external drive, but it doesn’t work. A diagram to explain what can go wrong, and how to fix it.
The Eclectic Light Company 