Sounds like the slow way of doing it. I use a piece of code in my /etc/profile that will make it so no one can log in except the users you want. If the file nologin exists in the etc directory only your special users can log in. Just do the following: touch /etc/nologin when you want no one except people in your list to login. rm /etc/nologin to turn it off. You can make this list as long or as short as you want.
if [ -r /etc/nologin ]
then
case $LOGNAME in
root);;
bmarkus);;
oracle);;
esac
fi
Hope this helps,
Brian
When a sys-admin say's maybe, they don't mean 'yes'!