1.目的

     因为图形界面比较占用资源，在部署中为了不浪费资源，我们一般使用命令行界面，有需要的时候使用命令startx切换到图形界面  

2.查看/etc/inittab文件，cat /etc/inittab

[root@zabbix-elk ~]# cat /etc/inittab 

# inittab is no longer used when using systemd.

#

# ADDING CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM.

#

# Ctrl-Alt-Delete is handled by /usr/lib/systemd/system/ctrl-alt-del.target

#

# systemd uses ‘targets‘ instead of runlevels. By default, there are two main targets:

#

# multi-user.target: analogous to runlevel 3  #命令行界面

# graphical.target: analogous to runlevel 5    #图形界面

#

# To view current default target, run:

# systemctl get-default

#

# To set a default target, run:

# systemctl set-default TARGET.target

#

3.查看当前默认模式

使用命令：systemctl get-default查看

[root@zabbix-elk ~]# systemctl get-default 

multi-user.target

[root@zabbix-elk ~]# 

4.设置默认模式

使用命令：systemctl set-default TARGET.target设置默认模式

systemctl set-default multi-user.target

systemctl set-default graphical.target

[root@zabbix-elk ~]# systemctl set-default multi-user.target 

Removed symlink /etc/systemd/system/default.target.

Created symlink from /etc/systemd/system/default.target to /usr/lib/systemd/system/multi-user.target.

[root@zabbix-elk ~]# systemctl set-default graphical.target 

Removed symlink /etc/systemd/system/default.target.

Created symlink from /etc/systemd/system/default.target to /usr/lib/systemd/system/graphical.target.

5.重启验证

命令行模式切换到图形界面运行命令：startx

图形界面切换到命令行界面使用：CTRL+ALT+F3

命令行界面切换到图形界面使用：CTRL+ALT+F5

Centos7更改默认启动模式