Thanks Jeff for sharing this!
You backuped the complete mmc in Backing up Your Root File System
with 'dd'
That's not always necessary, i simply mount for a quick rootfs only backup:
- sudo mount -o loop edison-image-edison.ext4 ./<directory name>
and then i do a 'rsync -avi --delete --exclude <mountpoint> '/' to this mountpoint
But it's not recommendable if the kernel version has been changed.
Another note:
'/home' has an extra partition in Ubilinux and if you don't need much space there you can rsync (duplicate) the rootfs to this place.
This has the advantage to have two bootable systems using the same kernel on the mmc. To choose this for booting change the "setenv" parameter in u-boot during bootup.