How Is LInux LOader (LILO) Configured?

LILO is configured through its configuration file named lilo.conf, which is found in the /etc
directory. As with other Linux configuration files, /etc/lilo.conf is a text file that can be modified in your favorite editor. Some of the information found in /etc/lilo.conf provides guidance to LILO for its operation. Other data in the file contains information specific to each operating system that LILO will boot. The following dialog shows a real-world sample of an /etc/lilo.conf file on a SuSE 6.2 system.

stimpy $ more /etc/lilo.conf
# LILO configuration file
# begin LILO global Section
boot=/dev/hda6
#compact # faster, but won't work on all systems.
vga = normal # force sane state
read-only
prompt
timeout=20
# End LILO global Section
# begin operating system specific section(s)
image = /boot/vmlinuz
root = /dev/hda6
label = SuSE
stimpy $
As a point of contrast, the following is an /etc/lilo.conf for RedHat 6.0 on the same computer.
stimpy $ more /mnt/redhat/etc/lilo.conf
boot=/dev/hda5
map=/boot/map
install=/boot/boot.b
prompt
timeout=50
# os specific
image=/boot/vmlinuz-2.2.5-15
label=linux
root=/dev/hda5
read-only
other=/dev/hda1
label=dos
table=/dev/hda
stimpy $

The label line refers to the text that is displayed in the LILO boot menu list. This is the text identifier that you type to boot the associated operating system. As mentioned previously, the first few lines pertain to LILO's general operation and the operating system specific entries follow.

Notice in the previous /etc/lilo.conf examples that the boot entry identifies a logical partition where
the Linux system is installed. If LILO were configured as the primary boot loader, the boot entry
would be boot=/dev/hda. This particular machine uses System Commander as the primary boot
manager. Based on the Linux operating system chosen, System Commander loads the appropriate
LILO boot loader, which is installed on the (associated) Linux logical partition.

LILO is a versatile and very flexible boot loader for Linux.  It does not depend on some particular file system; it can boot the Linux kernel images from floppy disks and hard disks, and it can even boot other operating systems.  1 of up to 16 different images can be selected at the boot time.  Many different parameters, such as the root device, can be set independently for each kernel.

LILO (Linux LOader) can even be used as the master boot record. If we want to configure LILO, you can do it by simply editing the lilo.conf file. When the very first time we install Linux, the install program usually steps us through the process of automatically generating a lilo.conf file. All of the global settings within the lilo.conf file can be changed. The settings can be overwritten by simply putting a replacement in the individual kernel parameters. We can configure our LILO by making the desired changes in lilo.conf file. After making changes in the file, to write out the lilo.conf and making our system bootable, simply run the lilo from the boot prompt. Now if we ever want to remove Linux and LILO, we will be needed to make the LILO totally go away and the easiest way of this is to use the DOS/Win95's fdisk program.