(Pi) Server Image Backup Process

backup.txt

dd if=/dev/zero of=test.img bs=4096 count=10240 (can make larger)
fdisk test.img
use 'o'
then 'n', 'p', '1', '8192', '122879'
then 't', '1', 'c'
look up 'End' sector number of first partition, add 1
then 'n', 'p', '2', 'number calculated above', default full space end
then 'w'
...
firstnumber=Start sector (partition 1) * 512 (unit size)
secondnumber=Second Start sector (partition 2) * 512 (unit size)
losetup -o firstnumber /dev/loop1 ./test.img
losetup -o secondnumber /dev/loop2 ./test.img

mkfs.vfat -F32 /dev/loop1
mkfs.ext4 /dev/loop2

mkdir one; mkdir two
mount -o offset=firstnumber -t vfat test.img one
mount -o offset=secondnumber -t ext4 test.img two

...mount physical copy
rsync -r source destination

...shrink file system
resize2fs
...shrink partition
fdisk