Every Debian 8 Jessie AMI that I launch in Amazon Web Services is only putting the root OS onto an 8GB partition regardless of what I set the size to at launch time.
According to the folks at boostrap-vz it is a problem with newer growpart on Debian Jessie. Please peruse the full issue on Github for complete details: https://github.com/andsens/bootstrap-vz/issues/267
