1、查看系统默认级别
wuhs@s147:~$ systemctl get-default
graphical.target
2、修改启动级别为命令行
wuhs@s147:~$ sudo systemctl set-default multi-user.target
Removed /etc/systemd/system/default.target.
Created symlink /etc/systemd/system/default.target → /lib/systemd/system/multi-user.target.
3、修改启动级别为图形界面
wuhs@s147:~$ sudo systemctl set-default graphical.target
Removed /etc/systemd/system/default.target.
Created symlink /etc/systemd/system/default.target → /lib/systemd/system/graphical.target.