Intel Macs tell you why they last shut down, in the ‘shutdown cause code’ written to the log by their System Management Controller. What do Apple silicon Macs do?
shutdown
You discover your Mac has either restarted itself and is waiting for you to log in, or has simply shut itself down. How to find out why this happened, in Intel and Apple silicon.
Not only is loginwindow there in its full glory at the start of the user phase of startup, but it’s there until the bitter end.
Apple recommends an unusual procedure to fix this, which might also work with other models suffering sudden shutdowns.
What are the benefits to leaving your Mac running all the time? And the costs? Which should you choose to do?
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.
Is shutdown -r now better than reboot? What advantages does Finder’s Restart have over them? The answers are in these logs.
When your Mac seems unresponsive and its GUI frozen, you don’t have to reach for the Power button. Try connecting using ssh: it’s actually very simple and valuable.
Shutdown cause codes, wake reasons, ACPI, and sleep states – diagnosing problems from hardware events.
Some subtle improvements which make it much easier to use when working with saved logarchives. A final release candidate?
The Eclectic Light Company 