Mengaktifkan Root hanya untuk user wheel group

[guest01@localhost ~]$ su
Password:
[root@localhost guest01]#

vim /etc/pam.d/su

#%PAM-1.0
auth            sufficient      pam_rootok.so
# Uncomment the following line to implicitly trust users in the "wheel" group.
#auth           sufficient      pam_wheel.so trust use_uid #tidak perlu mengisi password ketika user mengetikkan su -
# Uncomment the following line to require a user to be in the "wheel" group.
auth           required        pam_wheel.so use_uid #harus mengisi password ketika user mengetikkan su -
auth            include         system-auth
account         sufficient      pam_succeed_if.so uid = 0 use_uid quiet
account         include         system-auth
password        include         system-auth
session         include         system-auth
session         optional        pam_xauth.so

vim /etc/group

root:x:0:
bin:x:1:bin,daemon
daemon:x:2:bin,daemon
sys:x:3:bin,adm
adm:x:4:adm,daemon
tty:x:5:
disk:x:6:
lp:x:7:daemon
mem:x:8:
kmem:x:9:
wheel:x:10:guest01
mail:x:12:mail,postfix,exim
uucp:x:14:
man:x:15:
games:x:20:
gopher:x:30:
video:x:39:
dip:x:40:
ftp:x:50:
lock:x:54: