Linux～启动管理。

CentOS 6.x 启动管理。

系统运行级别。

运行级别命令。

• 查看运行级别。

init 0 ——> 关机。
init 6 ——> 重启。

[root@localhost ~]# runlevel
N 3
# 上次 现在。

• 改变运行级别。

[root@localhost ~]# init 级别

• 系统默认运行级别。

[root@localhost ~]# cat /etc/inittab 
# 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:

系统启动过程。

CentOS 6.x 启动管理。

启动引导程序～grub。

系统修改模式。