My script to make a bootable mirror of my laptop drive.

mirror-backup

#!/bin/sh

set -e

if [ $(id -u) -ne 0 ]
then
    echo "Rerunning with sudo..."
    fullpath="$(readlink -f $0)"
    exec sudo $fullpath
fi

while true; do
    cat /proc/mounts | grep mirror && break
    sleep 1
done

ROOT=/media/data/mirror

/usr/bin/rsync -vPaxSHAX --delete --numeric-ids \
    / /media/data/mirror

#--exclude media/automnt/usb/ \

# include external disk if plugged in
if [ -d /media/automnt/usb/home ]; then
    /usr/bin/rsync -vPaxSHAX --delete --numeric-ids \
        /media/automnt/usb/ /media/data/mirror/media/automnt/usb
fi

# NOTE for disk move
# Mount from rescue disk
# Make filesystem
#mkfs.ext4 /mnt/new
# Sync data
#/usr/bin/rsync -PaxSHAX --delete --numeric-ids /mnt/old/ /mnt/new
# Then do the below, except without the fstab change.

### Make backup bootable
# change to use the mirror disk
sed -i -e 's/LABEL=root/LABEL=mirror/' ${ROOT}/etc/fstab

# required mounts
for fs in dev dev/pts sys proc ; do
	mount -o bind /${fs} ${ROOT}/${fs}
done

# dpkg-reconfigure is only needed if you need to run grub-install
#sudo chroot ${ROOT} dpkg-reconfigure grub-pc
chroot ${ROOT} update-grub
chroot ${ROOT} update-initramfs -u -k all

for fs in sys proc dev/pts dev ; do
	umount ${ROOT}/${fs}
done

# done
umount -v /media/data/mirror