I'm setting up an Ubuntu 11.04 server VM for use as a database server. It would make everyone's lives easier if we could have folks login using windows credentials and perhaps even make the machine work with the current AD-driven security we've got elsewhere.

The first leg of this was really easy to accomplish -- apt-get install likewise-open and I was pretty much in business. The problem I'm having is getting our admins into the sudoers groups -- I can't seem to get anything to take. I've tried:

a) usermod -aG sudoers [username]
b) adding the user names in several formats (DOMAIN\user, user@domain) to the sudoers file.

None of which seemed to take, I still get told "DOMAIN\user is not in the sudoers file. This incident will be reported."

So, how do I add non-local users to the sudoers?