The concept of runlevels in SysV has been reimagined and expressed as targets in `systemd`. Knowing how to manage, use, and manipulate targets will make your `systemd` management much easier.
In this lab, we’ll use the `runlevel` command that ships with `systemd` to determine system state, work with the default target, manipulate it, and then isolate to the new target.
We’ll also understand why some targets can be isolated and others can’t, inspect the contents of targets to see what they can do, and finally get a better understanding of the relationship between the `poweroff`, `shutdown`, `halt`, and `reboot` commands and `systemctl`.
Learning Objectives
Successfully complete this lab by achieving the following learning objectives:
- Work with Runlevels and Targets
- Use the runlevel command.
- Get and set the default target.
- Isolate and list the targets.
- Work with Target Isolation
- Attempt to isolate a target.
- List the contents of different targets.
- Determine what allows a target to be isolated.
- Understand the Shutdown Commands
- Identify the location of the
shutdown,halt,poweroff, andrebootcommands. - Determine what they are.
- See which are also represented in systemctl.
- Identify the location of the
