/etc/rc.d/init.d/nfs checks for the existence of
/etc/exports and if there isn't one, it doesn't start nfs.
This is good because of the general principle that you
should not run any unused internet services, because such
things are solely of use to "the bad guys" (if they're not
of use to you, by definition, because I'm talking about
unused services).

However, the "setup" package contains an empty /etc/exports
file.  This is too bad, because it means that a lot of
people are providing nfs service for no reason.

I suggest either not including /etc/exports in the setup
package, or changing the test -f /etc/exports in
/etc/rc.d/init.d/nfs (in the knfsd package) to a "-s" so
that it doesn't start nfs for a zero-length /etc/exports.