Here is what I have. I have Mandrake installed on /dev/hda5 (had its boot partition set up on the MBR I believe. I then installed Knoppix 3.3 using /dev/hda3. They shared the swap at /dev/hda2 and boot partition at /dev/hda1. Lilo will not recognize the Mandrake as a bootable partition. Here is the end of my lilo.conf file:

# If you have another OS on this machine to boot, you can uncomment the
# following lines, changing the device name on the `other' line to
# where your other OS' partition is.
#
other=/dev/hda5
label=Mandrake
# restricted
table=/dev/hda
alias=3

Am I doing this right? when I do /sbin/lilo, I get:

root@pos-linux:/home/ryan# lilo
Added Linux (alias 1) *
Skipping /vmlinuz.old
Fatal: First sector of /dev/hda5 doesn't have a valid boot signatur

any suggestions?

Other is for a non-Linux OS.

You need something like

image=/boot/mandrake-kernel-name
root=/dev/hda5
label=Mandrake
read-only

(Though I seem to also recall mandrake wanting initrd stuff.) Anyway - the LILO man page may help or you can search here for other people's configs - maybe 'Mandrake LILO configuration' or something.

It's possible there's another issue but you definitely need a Linux-type entry for Mandrake.

In addition to what Gates1026 said, look at that "fatal" error. You said above that you have hda1 'shared' for both Mandrake and Knoppix. You need a separate boot partition for each distro. It is fine to share the swap partition, but not the boot one. That is why the fatal error comes up - lilo looks for a boot signature where you say Mandrake is...

Well, actually you can share boot. But, true, dev/hda5 isn't bootable.