I am an intermidiate Linux user, and I have had some problems limiting
the usage of the 'su' command. I recently changed the name of the one
user account that is in the wheel group (which I know is one way to
limit who can the su to root), and while the user's new name stayed in
the wheel group, I was unable to su until I changed the name back.

Anyway, my question is, what are the different ways to limit who can su
to root? I know that gentoo comes configured so that only users of
wheel can su. How else can this be controlled?

Thanks in advance,
Dan