Recipe 12.18. Multibooting Linuxes with LILO
12.18.1 Problem
You would like to run several different
Linuxes on a single PC, and you want LILO for the bootloader.
12.18.2 Solution
The first Linux installed is the
"host" system. You need to preserve
it to keep LILO working. Make sure that the root filesystem
containing the /boot directory is on a primary
partition, or LILO won't work.
Write down the location of the partition where the root filesystem of
your next Linux is going to be installed. If you also know the exact
name of the kernel, and the initrd image (if
there is one), you're ahead of the game. While
you're still in the host Linux, you can create a
lilo.conf entry for Linux #2:
# Red Hat 9
image=/boot/vmlinuz-2.4.22-1
initrd=/boot/initrd-2.4.22-1.img
label="Red Hat 9"
root=/dev/hda6
read-only
Then write the changes to the MBR:
# /sbin/lilo -v
Now you can go ahead and install Linux #2, and because you already
have a LILO boot menu entry for it, you can glide through however
many reboots it takes to complete the installation.
When the installer gets to the bootloader installation, be sure to
select "install to the first sector of the root
partition," or however your installer words it. Do
not overwrite the MBR.
If you don't know the exact kernel name and
initrd image, you'll have to
discover them from the host Linux. Go ahead and start the
installation of Linux #2. When it comes to the first reboot,
you'll end up back in the host Linux. Mount the new
Linux #2 filesystem and read the /boot
directory:
# mount /dev/hda6 /mnt/tmp
# cd /mnt/tmp
# ls boot
System.map initrd-2.4.22-1.img System.map-2.4.22-1 vmlinuz vmlinuz-2.4.22-1
There's your kernel and initrd.
Make your lilo.conf entry, re-run
/sbin/lilo, and reboot. Now you can select your
new Linux from the bootloader menu and finish the installation.
12.18.3 Discussion
Sometimes a ramdisk is required for the system
to boot properly. If this is the case, there will be an
initrd image. Note that not all distributions
require an initrd image. If
it's in /boot,
it's needed, and it requires an entry in
lilo.conf.
12.18.4 See Also
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