Create and restore a Backup of a complete data carrier

The best way to backup the Raspberry Pi is to create an image of the entire SD card.  

This is best done with the tool dd  (/dev/sdb is the volume to be backed up).

The command is as follows:

sudo dd if=/dev/sdb of=/home/Dokumente/Backup.img bs=1M && sync 

Restore the disk from the image with dd

First, clean up the destination drive:

sudo dd if=/dev/urandom of=/dev/sdb bs=1M && sync 

Then play back the image:

sudo dd if=Backup.img of=/dev/sdb bs=1M && sync