do-release-upgrade

Hey all, So, I know you configure the network interfaces for new containers in the web interface (or by editing the corresponding config file in /etc/pve/lxc) but how does it work when you actually power up the container? The reason I ask is, I have a bunch of Ubuntu 14.04 based containers...

So, tried upgrading a container running 14.04 -> 16.04. The container was fully patched prior to running the do-release-upgrade. Tried to restart container once that completed and now the container completely refuses to boot! Hoping somebody can help figure out why, I have been poking around...