The following script, or any script like it will not work. Do not waste your time and end up hosing your box like I did today:

#!/bin/bash

echo "==> installing cdebootstrap"
apt-get install cdebootstrap

echo "==> reticulating splines"
dpkg -l | cut -f3 -d' ' >> /tmp/packages.installed
pkg=`cat /tmp/packages.installed | xargs`
pkg=`echo $pkg | sed -e 's#bunch of crap elided here##g'`

echo "==> installing libc6-amd64"
apt-get install libc6-amd64

echo "==> installing base system"
cdebootstrap -a amd64 lenny /

for pkg in $pkg; do
echo "==> reinstalling $pkg"
apt-get install --reinstall --force-yes $pkg
done

Don’t let this happen to you. I had the pleasure of discovering that Bacula was not properly backing up my MySQL databases. What an excellent way of finding out.