In this chapter, we interacted with runlevels. We saw the various runlevels available, and we switched between runlevels. We saw the default runlevel (runlevel 5), and we made usage of the runlevel, who, and init commands for interaction. We then focused on boot targets. We looked at the default boot targets and saw the various units under each boot target. We then changed between boot targets and saw that authentication was required. We used the systemctl commands with various options, and the runlevel and who commands. We verified we are indeed in another boot target. We derived that the graphical.target is similar to runlevel 5 and that multi-user.target is similar to runlevel 3. Finally, we took a brief looked at the structure of a boot target.
In the next chapter, we will focus on the design of a hard disk layout. The hard disk layout is critical before any deployment...