Something

#!/bin/sh

if [ `id -u` != "0" ]; then
	echo "Not running as root!"
	exit 2
fi

# Separate with a space. Exclude trailing slash!
SOURCES="/"
TARGET="/mnt/hda2"
TARGETDEV="/mnt/hda2"

# dirs and files to be excluded, one per line.
# /proc/
# *.bak
EXCLUDE_FILE="/usr/local/share/backup-hda2-exclude.txt"

TARGETMOUNTED=0

echo "Verifying target..." 
if [ ! -d $TARGET/home ]; then
	echo "Backup target is not mounted. Mounting..."
	mount $TARGETDEV
	if [ ! -d $TARGET/home ]; then
		echo "Backup target does not exist or is not mountable!"
		echo "Exiting..."
		exit 2
	else export TARGETMOUNTED=1
	fi
else export TARGETMOUNTED=2
fi

echo "Target verified."

echo "Verifying sources..." 
for source in $SOURCES; do
	echo "Checking $source..."
	if [ ! -x $source ]; then
	echo "Backup source does not exist!"
	echo "Exiting..."
	exit 2
fi
done

if [ -f $EXCLUDE_FILE ]; then
EXCLUDE="--exclude-from=$EXCLUDE_FILE"
fi

echo "Sources verified."

for source in $SOURCES; do
		if [ ! -d $TARGET/$source ]; then
			echo "Mimicking sources directory hierarchy..."
			mkdir -p $TARGET/$source
		fi
	echo "Running rsync..."
	ionice -c3 nice -n19 rsync --progress --exclude=$TARGET/ $EXCLUDE -a --delete $source/ $TARGET/$source/ "$@"
done

if [ $TARGETMOUNTED = 1 ]; then
	sleep 2
	umount $TARGETDEV
	if [ -d $TARGET/home ]; then
		echo "Backup target still mounted!"
		echo "Exiting..."
		exit 1
	fi
	echo "Backup target unmounted."
fi
if [ $TARGETMOUNTED = 2 ]; then
	echo "Backup target was mounted and will remain mounted."
fi

exit 0