Installing Debian over a Fedora 12 system

[James Allsopp <jamesaallsopp@googlemail.com>]

Hi,
I've a Fedora 12 system which I'm distinctly unimpressed by, and want to
install Debian. It's currently set up with two 1 tb drives. These both
have a 250 Mb boot partition and then the rest is a RAID 1, hosting LVM
for the other partitions. Am I going to have to back up all of my data
in home (separate partition) and start a new structure or is there a
simple way of installing debian and have it recognise the existing
structure? The partitions are all EXT4 except boot which is EXT3.

Thank you for any advice. I'll probably back up home to be on the safe
side anyway!

Jim