显示的机器是通过Pam认证来进行，在／etc/pam.d/下面也有关于halt，reboot，poweroff命令的一些规则，当然还有一点就是这些命令本身设置的权限问题，例如：
[root@F7 sbin]# pwd
/sbin
[root@F7 sbin]# ls -l halt poweroff reboot
-rwxr-xr-x 1 root root 12360 2007-05-04 halt
lrwxrwxrwx 1 root root 4 2007-05-29 poweroff -> halt
lrwxrwxrwx 1 root root 4 2007-05-29 reboot -> halt
[root@F7 sbin]#
[root@F7 security]# pwd
/etc/security
[root@F7 security]# ls
access.conf console.perms namespace.conf pam_winbind.conf
chroot.conf console.perms.d namespace.init time.conf
console.apps group.conf opasswd
console.handlers limits.conf pam_env.conf
[root@F7 security]# cd console.apps
[root@F7 console.apps]# pwd
/etc/security/console.apps (该文件夹下面的文件来进行控制，如果让普通用户不能重启的或者关机的话，你可以把halt ,reboot poweroff 文件删除就可以了）
[root@F7 console.apps]# ls
authconfig pm-suspend system-config-network-cmd
authconfig-gtk pm-suspend-hybrid system-config-nfs
authconfig-tui poweroff system-config-printer
cpufreq-selector pup system-config-samba
dateconfig reboot system-config-securitylevel
eject serviceconf system-config-selinux
gdmsetup setup system-config-services
gnome-system-log system-cdinstall-helper system-config-soundcard
halt system-config-authentication system-config-time
kbdrate system-config-date system-config-users
kppp system-config-display system-install-packages
neat system-config-httpd virt-manager
pirut system-config-keyboard vm_applet_wrapper
pm-hibernate system-config-language
pm-powersave system-config-network
[root@F7 console.apps]#
