Is the CromeOs kernel fully multi user? about crouton HOT 1 CLOSED

Yep, it's a recent, fairly stock Gentoo kernel, complete with crazy fancy things such as multi-user support, so you can live as an unprivileged user and sudo whenever you need something more.

You can control which release you initially install using -r. As for upgrading, I have not tested the standard update manager, so I don't know how well that will work. A slightly more dangerous way of upgrading would be changing the /etc/apt/sources.list file to refer to the new release explicitly, then doing sudo apt-get update && sudo apt-get dist-upgrade, but you won't get the benefits of whatever automated migration the upgrade manager does.

It should be easy to test for yourself though (and then report back here, please!). Create a new chroot with an older release (or go with the default precise), then install the update manager and see how well it works.

from crouton.