查看/etc/inittab如下
# systemd uses 'targets' instead of runlevels.
# by default, there are two main targets:
#
# multi-user.target: analogous to runlevel 3
# graphical.target: analogous to runlevel 5
#
# To view current default target, run:
# systemctl get-default
#
# To set a default target, run:
# systemctl set-default TARGET.target
新版本的CentOS系统里使用targets取代了运行级别的概念。系统有两种默认的targets，多用户.target对应之前版本的3运行级别；而图形.target对应之前的5运行级别。
查看默认的target
systemctl get-default
开机以命令模式启动
systemctl set-default multi-user.target
开机以图形界面启动
systemctl set-default graphical.target
