编辑/etc/inittab文件

# inittab is only used by upstart for the default runlevel.
#
# ADDING OTHER CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM.
#
# System initialization is started by /etc/init/rcS.conf
#
# Individual runlevels are started by /etc/init/rc.conf
#
# Ctrl-Alt-Delete is handled by /etc/init/control-alt-delete.conf
#
# Terminal gettys are handled by /etc/init/tty.conf and /etc/init/serial.conf,
# with configuration in /etc/sysconfig/init.
#
# For information on how to write upstart event handlers, or how
# upstart works, see init(5), init(8), and initctl(8).
#
# Default runlevel. The runlevels used are:
#   0 - halt (Do NOT set initdefault to this)
#   1 - Single user mode
#   2 - Multiuser, without NFS (The same as 3, if you do not have networking)
#   3 - Full multiuser mode
#   4 - unused
#   5 - X11
#   6 - reboot (Do NOT set initdefault to this)
#
id:3:initdefault:

找到这行代码：id:3:initdefault:

它定义Linux进入系统后执行的init动作级别，共有以下6个级别：

级别0，挂起、关机模式;

级别1，单用户模式;

级别2，多用户模式，但没有网络功能;

级别3，全功能的单用户模式;

级别4，没用到;

级别5，X11模式，也就是图形化界面模式;

级别6，重起模式。

将原来的“3”修改成“5”，然后reboot重启系统即可。

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