Modifying the boot level of Linux CentOS 6 and CentOS 7

CentOS 6 Change the boot level of the system is simple, directly modify the file: /etc/inittab , the last line in the file to modify.

Path to the CentOS 7 system-level modification:
/etc/systemd/system/default.target
The file is a soft link that modifies the process such as:

查看当前运行在哪个级别上执行：    `systemctl get-default`

view the corresponding relationships (soft connections) for the runlevel in CentOS7, such as:

Modifying the boot level of Linux CentOS 6 and CentOS 7