The LILO configuration file is /etc/lilo.conf. The /sbin/lilo commands uses this file to determine what information to write to the MBR.
Before editing /etc/lilo.conf, be sure to make a backup copy of the file. Also, have a working boot floppy available so that changes can be made to the MBR if there is a problem. See the man page for mkbootdisk for more information on creating a boot disk.
The /etc/lilo.conf file is used by the /sbin/lilo command to determine which operating system or kernel to load and where it should be installed.
A sample /etc/lilo.conf file looks like this:
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 label=linux initrd=/boot/initrd-2.4.0-0.43.6.img read-only root=/dev/hda5 other=/dev/hda1 label=dos
This example shows a system configured to boot two operating systems: Red Hat Linux and DOS. Next is a more detailed look at the lines of this file:
boot=/dev/hda — Instructs LILO to install itself on the first hard disk of the first IDE controller.
map=/boot/map — Locates the map file. In normal use, this should not be modified.
install=/boot/boot.b — Instructs LILO to install the specified file as the new boot sector. In normal use, this should not be altered. If the install line is missing, LILO will assume a default of /boot/boot.b as the file to be used.
prompt — Instructs LILO to show you
whatever is referenced in the message line. While
it is not recommended that you remove the prompt
line, if you do remove it, you can still access a prompt by holding
timeout=50 — Sets the amount of time that LILO will wait for user input before proceeding with booting the default line entry. This is measured in tenths of a second, with 50 as the default.
message=/boot/message — Refers to the screen that LILO displays to let you select the operating system or kernel to boot.
lba32 — Describes the hard disk geometry to LILO. Another common entry here is linear. You should not change this line unless you are very aware of what you are doing. Otherwise, you could put your system in an unbootable state.
default=linux — Refers to the default operating system for LILO to boot as seen in the options listed below this line. The name linux refers to the label line below in each of the boot options.
image=/boot/vmlinuz-2.4.0-0.43.6 — Specifies which Linux kernel to boot with this particular boot option.
label=linux — Names the operating system option in the LILO screen. In this case, it is also the name referred to by the default line.
initrd=/boot/initrd-2.4.0-0.43.6.img — Refers to the initial ram disk image that is used at boot time to actually initialize and start the devices that makes booting the kernel possible. The initial ram disk is a collection of machine-specific drivers necessary to operate a SCSI card, hard drive, or any other device needed to load the kernel. You should never try to share initial ram disks between machines.
read-only — Specifies that the root partition (see the root line below) is read-only and cannot be altered during the boot process.
root=/dev/hda5 — Specifies which disk partition to use as the root partition.
other=/dev/hda1 — Specifies the partition containing DOS.