一、停止邮件服务
[root@localhost ~]# systemctl stop postfix # 临时关闭

[root@localhost ~]# systemctl disable postfix # 永久关闭
Removed symlink /etc/systemd/system/multi-user.target.wants/postfix.service.
[root@localhost ~]#

二、停止打印服务：
[root@localhost ~]# systemctl stop cups.path # 临时关闭
[root@localhost ~]# systemctl stop cups.socket # 临时关闭
[root@localhost ~]# systemctl stop cups.service # 临时关闭

[root@localhost ~]# systemctl disable cups.path # 永久关闭
Removed symlink /etc/systemd/system/multi-user.target.wants/cups.path.
[root@localhost ~]# systemctl disable cups.socket # 永久关闭
Removed symlink /etc/systemd/system/sockets.target.wants/cups.socket.
[root@localhost ~]# systemctl disable cups.service # 永久关闭
Removed symlink /etc/systemd/system/multi-user.target.wants/cups.service.
Removed symlink /etc/systemd/system/printer.target.wants/cups.service.
[root@localhost ~]#

三、停止rpcbind：
[root@localhost ~]# systemctl stop rpcbind.socket # 临时关闭
[root@localhost ~]# systemctl stop rpcbind # 临时关闭

[root@localhost ~]# systemctl disable rpcbind.socket # 永久关闭
Removed symlink /etc/systemd/system/sockets.target.wants/rpcbind.socket.
[root@localhost ~]# systemctl disable rpcbind # 永久关闭
[root@localhost ~]#

四、关闭SELinux，将 /etc/sysconfig/selinux 中的 SELinux=enforcing 修改为 SELinux=disabled
临时关闭，重启失效：
#setenforce 0
#getenforce

五、关闭firewall：
#停止firewall
systemctl stop firewalld.service 

#禁止firewall开机启动
systemctl disable firewalld.service 

#查看默认防火墙状态（关闭后显示notrunning，开启后显示running）
firewall-cmd --state

六、关闭NetworkManager

    # systemctl stop NetworkManager        # 临时关闭
    # systemctl disable NetworkManager   # 永久关闭网络管理命令