Grabbed some commands from this article.

It will install debian on swap partition.

Disable swap

swapoff -a

Change id for the swap partition to 83 with t command

fdisk /dev/sda

Create fs on swap partition

mke2fs -j /dev/sdaX

Mount partition and run debian bootstrap

export LFS=/mnt/lfs

mkdir -p $LFS

mount /dev/sdaX $LFS

/usr/sbin/debootstrap --arch i386 lenny $LFS http://http.us.debian.org/debian

Copy required files from the host OS

cp /etc/resolv.conf $LFS/etc/resolv.conf
cp /etc/hosts $LFS/etc/hosts
cp /etc/hostname $LFS/etc/hostname

Update fstab, login in a chroot environment.

chroot $LFS /usr/bin/env -i HOME=/root \
    TERM=$TERM PS1='\u:\w\$ ' PATH=/bin:/usr/bin:/sbin:/usr/sbin \
    /bin/bash --login

Edit /etc/fstab with nano and add below content

# filesystem   mount-point fs-type    options     dump    fsck-order
/dev/sdaX      /           auto       defaults    0       1
proc           /proc       proc       defaults    0       0

Mount proc in chroot

mount -t proc proc /proc

Set hostname

hostname srv.example.com

Install aother packages

apt-get update
apt-get install console-data locales mc rootstrap

Configure network

nano /etc/network/interfaces

Install kernel

apt-cache search linux-image

mount --bind /boot $LFS/boot

apt-get install linux-image-2.6.24-1-686

Install discover for hardware detection

apt-get install discover

Umount and reboot

umount $LFS/proc
umount $LFS

shutdown -r now

You should have the debian OS installed after reboot. You can now manage other bigger disks and adapt installation.