backup/resume sd with three partitions (boot, system, contents). Made for Rapsberry Pi

raspi-sd.sh

#!/bin/bash

ACTION=$1
SRC=$2
DST=$3

function pull {
  mkdir "${DST}"
  cd "${DST}"
  mkdir mnt mnt/1 mnt/2 mnt/3
  mount -o ro "${SRC}1" mnt/1
  mount -o ro "${SRC}2" mnt/2
  mount -o ro "${SRC}3" mnt/3
  ( cd mnt/1 && tar cpvf ../../1.tar . )
  ( cd mnt/2 && tar cpvf ../../2.tar . )
  ( cd mnt/3 && tar cpvf ../../3.tar . )
  umount mnt/1
  umount mnt/2
  umount mnt/3
  rmdir mnt/1 mnt/2 mnt/3 mnt
}

function fdisk_batch {
cat <<EOF
n
p
1

+32M
t
b
n
p
2

+4G
n
p
3


w
EOF
}

function push {
  dd if=/dev/zero of="${DST}" bs=512 count=1
  fdisk_batch | fdisk "${DST}"
  sleep 1
  cd "${SRC}"
  mkdir mnt mnt/1 mnt/2 mnt/3
  mkfs.vfat -n BOOT  "${DST}1"
  mkfs.ext4 -L LINUX "${DST}2"
  mkfs.ext4 -L MOD   "${DST}3"
  sleep 1
  mount "${DST}1" mnt/1
  mount "${DST}2" mnt/2
  mount "${DST}3" mnt/3
  ( cd mnt/1 && tar xpvf ../../1.tar )
  ( cd mnt/2 && tar xpvf ../../2.tar )
  ( cd mnt/3 && tar xpvf ../../3.tar )
  echo
  echo
  read -p "hostname: " hostname
  echo ${hostname} > mnt/2/etc/hostname
  umount mnt/1
  umount mnt/2
  umount mnt/3
  rmdir mnt/1 mnt/2 mnt/3 mnt
}

case $ACTION in
  pull) pull
    ;;
  push) push
    ;;
esac