[...]If I do this I get a Fatal: Duplicate geometry definition for /dev/md0 My boot=/dev/md1...hmmh :-(
Here's my lilo.conf from a system where I can boot from either drive in the RAID.
prompt timeout=50 default=linux boot=/dev/md0 map=/boot/map install=/boot/boot.b message=/boot/message linear
image=/boot/vmlinuz-2.4.20-8smp label=linux initrd=/boot/initrd-2.4.20-8smp.img read-only root=/dev/md1
disk=/dev/md0 partition=/dev/md1
-- daniel