CHAPTER 15

The Boot Process

IN THIS CHAPTER

Running Services    at  Boot

Beginning   the Boot    Loading Process

Starting    and Stopping    Services    Manually

Using   Upstart

Using   systemd

Boot-Repair

References

In this chapter, you learn about making tasks into services that run as your

system starts and making them into services you can start and stop by hand.
You also learn about the entire boot process.

After you turn on the power switch, the boot process begins with the
computer executing code stored in a chip called the BIOS, or basic
input/output system; this process occurs no matter what operating system you
have installed. The Linux boot process begins when the code known as the
boot loader starts loading the Linux kernel and ends when the login prompt
appears.

As a system administrator, you will use the skills you learn in this chapter to
control your system’s services and manage runlevels on your computer.
Understanding the management of the system services and states is essential
to understanding how Linux works (especially in a multiuser environment)
and helps untangle the mysteries of a few of your Ubuntu system’s
configuration files. Furthermore, a good knowledge of the cron daemon that
handles task scheduling is essential for administrators at all skill levels, so
you will want to combine this knowledge with what you learned in Chapter
14 , “Automating Tasks and Shell Scripting.”