stuck on backup and restore process

I'm confident the issue is something small which is really frustrating. I'm going to try to be thorough in my documentation and provide the needed info.

Goal - do a complete backup of my UB16.04 notebook so I can install different linux distribs, experiment, break stuff and then easily restore back to last good backup.

My steps:
After complete install of UB16.04, I have all my programs installed, settings configured, everything is working great. I then do a backup using this wiki , specifically I use this command in a term window in the root directory:

tar -cvpzf backup.tar.gz --exclude=/backup.tar.gz --one-file-system /