Chapter 9: Services and the boot process

Manage services with systemd, write your own units, understand the boot sequence and targets, and recover a system that will not boot normally.

What you will learn

Start, stop, enable, disable and mask services, and separate "running now" from "starts at boot".
Write a service unit, override it with a drop-in, and diagnose a unit that will not start.
Describe the boot sequence, set the default target, read boot timing and change kernel arguments.
Recover from a lost root password or a bad /etc/fstab using console access.