inittab文件

CentOS5.8：

#
# inittab       This file describes how the INIT process should set up
#               the system in a certain run-level.###
###该文件描述了INIT进程应设置系统在一定的运行级别。
#
# Author:       Miquel van Smoorenburg, <[email protected]>
#               Modified for RHS Linux by Marc Ewing and Donnie Barnes
#
# Default runlevel. The runlevels used by RHS are:
#   0 - halt (Do NOT set initdefault to this)  ###关机
#   1 - Single user mode        ###单用户模式
#   2 - Multiuser, without NFS (The same as 3, if you do not have networking) ###与3相似，只是没有NFS
#   3 - Full multiuser mode  ###完整含有网络的纯文本模式
#   4 �C unused  ###系统保留
#   5 - X11     ###与3类似，但加载使用X window
#   6 - reboot (Do NOT set initdefault to this) ###重启
#
id:3:initdefault:   ###预设的runlevel，此runlevel为3
# System initialization.
si::sysinit:/etc/rc.d/rc.sysinit  ###准备系统软件执行的环境的脚本文档
##7个不同的服务，需要启动服务的scripts的放置路径
l0:0:wait:/etc/rc.d/rc 0     0 在/etc/rc.d/rc0.d/
l1:1:wait:/etc/rc.d/rc 1     1 在/etc/rc.d/rc1.d/
l2:2:wait:/etc/rc.d/rc 2     2 在/etc/rc.d/rc2.d/
l3:3:wait:/etc/rc.d/rc 3     3 在/etc/rc.d/rc3.d/
l4:4:wait:/etc/rc.d/rc 4     4 在/etc/rc.d/rc4.d/
l5:5:wait:/etc/rc.d/rc 5     5 在/etc/rc.d/rc5.d/
l6:6:wait:/etc/rc.d/rc 6     6 在/etc/rc.d/rc6.d
# Trap CTRL-ALT-DELETE  ###是否允许按下ctrl+alt+del就重新启动的设定项目
ca::ctrlaltdel:/sbin/shutdown -t3 -r now
# When our UPS tells us power has failed, assume we have a few minutes
# of power left.  Schedule a shutdown for 2 minutes from now.
###当ups电源电量低时，假设还有几分钟的时间。现在做一个两分钟内关机的计划。
# This does, of course, assume you have powerd installed and your
# UPS connected and working correctly.  ###假设电源正常
pf::powerfail:/sbin/shutdown -f -h +2 "Power Failure; System Shutting Down" ###没电，关机
# If power was restored before the shutdown kicked in, cancel it.
###如果在关机前电源恢复，则取消关机。
pr:12345:powerokwait:/sbin/shutdown -c "Power Restored; Shutdown Cancelled"
####tty1~tty6是由底下这6行决定的
# Run gettys in standard runlevels ###在标准运行级别运行的getty
1:2345:respawn:/sbin/mingetty tty1  ###respawn 复位
2:2345:respawn:/sbin/mingetty tty2
3:2345:respawn:/sbin/mingetty tty3
4:2345:respawn:/sbin/mingetty tty4
5:2345:respawn:/sbin/mingetty tty5
6:2345:respawn:/sbin/mingetty tty6
###此处决定X window
# Run xdm in runlevel 5 
x:6:respawn:/etc/X11/prefdm �Cnodaemon

CentOS 6.4

# 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: