LPI Linux Certification in a Nutshell, 2nd Edition

Objective 1: Boot the System

It is the job of a boot loader, such as LILO or GRUB, to launch the Linux kernel at boot time. In some cases, the boot loader has to deliver information to the Linux kernel that may be required to configure peripherals or control other behavior. This information is called a kernel parameter.

Boot-time Kernel Parameters

By default, your system's kernel parameters are set in your boot loader's configuration file (/etc/lilo.conf or /boot/grub/menu.lst, and boot/grub/grub.conf on Red Hat and some other distributions). However, the Linux kernel also has the capability to accept information at boot time from a kernel command-line interface. You access the kernel command line through your installed boot loader. When your system boots, you can interrupt the "default" boot process when the boot loader displays and specify your desired kernel parameters. The kernel parameters on the command line look similar to giving arguments or options to a program during command-line execution.

For an example, let's say you wanted to boot with a root partition other than your default, /dev/hda1. Using LILO, you could enter the following at the LILO prompt:

LILO: linux root=/dev/hda9

This command boots the kernel whose label is linux and overrides the default value of /dev/hda1 to /dev/hda9 for the root filesystem.

On the Exam

There are far too many kernel parameters to list in this book. Consequently, you must familiarize yourself with them in general terms so that you can answer ...