A script to capture config info:

#!/bin/bash

#as root

TIME_STAMP=`date +"%G-%m-%d-%H%M%S"`
RESCUE_DIR="/root/rescue/${TIME_STAMP}"

mkdir -p ${RESCUE_DIR}

dpkg --get-selections > "${RESCUE_DIR}/dpkg-selections.out"
dpkg --get-selections | grep -v deinstall > "${RESCUE_DIR}/dpkg-selections-without-deinstall.out"
fdisk -l > "${RESCUE_DIR}/fdisk.out"
df > "${RESCUE_DIR}/df.out"
mount > "${RESCUE_DIR}/mount.out"
if [ -f /sbin/iptables-save ]; then
  iptables-save > "${RESCUE_DIR}/iptables.out"
fi
if [ -f /usr/bin/gem ]; then
  gem list > "${RESCUE_DIR}/gems.out"
fi

cd /var/spool/cron
tar czvf "${RESCUE_DIR}/crontabs.tar.gz" crontabs