Given a Raspberry Pi with Rasbian, you'll need to backup your sdk every now and then.
(courtesy of @nickbauman)
Requires public key exchange for pi account:
ssh pi@raspberry sudo dd if=/dev/mmcblk0 | gzip -c > raspberry.img.gz
Requires locally mounted disk device rdisk1:
gzip -dc /path/to/raspberry.img.gz | sudo dd of=/dev/rdisk1 bs=1m