Chapter 4. Boot Loaders

85

4.8.2. LILO vs. GRUB

In general, LILO works similarly to GRUB except for three major differences:

It has no interactive command interface.

It stores information about the location of the kernel or other operating system it is to load on the

MBR.

It cannot read ext2 partitions.

The first point means the command prompt for LILO is not interactive and only allows one command

with arguments.

The last two points mean that if you change LILO's configuration file or install a new kernel, you must

rewrite the Stage 1 LILO boot loader to the MBR by issuing the

/sbin/lilo  v  v

command. This

is more risky than GRUB's method, because a misconfigured MBR leaves the system unbootable.

With GRUB, if the configuration file is erroneously configured, it will simply default to its command

line interface.

Tip

If you upgrade the kernel using the Red Hat Update Agent, the MBR will be updated automatically.

For more information on RHN, refer to the following URL, https://rhn.redhat.com

4.9. Options in

/etc/lilo.conf

The

/sbin/lilo  v  v

command accesses the LILO configuration file,

/etc/lilo.conf

, to de 

termine what to write to the MBR. If you are planning on using the

lilo

command, you need to know

how to edit this file.

Warning

If you are planning to edit /etc/lilo.conf, be sure to make a backup copy of the file before making

any changes. Also, be sure that you have a working boot floppy available so that you will be able

to boot the system and make changes to the MBR if there is a problem. See the man pages for

mkbootdisk for more information on creating a boot disk.

The file

/etc/lilo.conf

is used by

lilo

to determine which operating system or kernel to start,

as well as to know where to install itself (for example,

/dev/hda

for the first MBR of the first IDE

hard drive). A sample

/etc/lilo.conf

file looks like this (your

/etc/lilo.conf

may look a little

different):

boot=/dev/hda

map=/boot/map

install=/boot/boot.b

prompt

timeout=50

message=/boot/message

lba32

default=linux

image=/boot/vmlinuz 2.4.0 0.43.6