https://github.com/lzkelley/bkup_rpimage
git clone https://github.com/lzkelley/bkup_rpimage
create /mnt/disk directory
insert usb stick. (disk size > system sd_card)
mount /dev/sda1 /mnt/disk #/dev/sda1 from usb stick
bkup_rpimage.sh at bkup_rpimage directory #from git clone
sudo sh bkup_rpimage.sh start -c /mnt/disk/rpi_backup.img #backup to /mnt/disk/rpi_backup.img
raspberry pi system backup in /mnt/disk/rpi_backup.img
