Linux inittab 配置文件

浏览数：19 / 时间：2015年06月20日

一、声明

本人实验的环境是 Centos 6.5.

二、介绍

在Linux系统中，进程号为1的程序是init，init进程是所有进程的起点并且管理所有进程。

init进程在运行时会调用/etc/inittab配置文件，inittab文件描述了几种不同的init进程运行级别。

三、文件内容

# 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:5:initdefault:

从文件内容可以发现，总共有6个不同的运行级别（runlevel），并且通过类似 id:5:initdefault: 的命令来指定init进程运行的不同级别。