在systemd里面，可以直接使用systemctl进行管理
启动：systemctl start NetworkManger
关闭：systemctl stop NetworkManager
开机启动：systemctl enable NetworkManger
查看是否开机启动：systemctl is-enabled NetworkManager
禁用开机启动：systemctl disable NetworkManager
启动：service NetworkManager start
关闭：service NetworkManager stop
开机启动：chkconfig NetworkManager on
禁用开机启动：chkconfig NetworkManager off