Linux boot Process CentOS6

1. Operating level

0 Turn off the machine

1 single-user mode, can be imagined as Windows security mode, mainly used with system repair

2 Incomplete command-line mode with no NFS service

3 full command-line mode, which is the standard character interface

4 system Retention

5 Image Mode

6 restart

2. Operating level

RunLevel View Run level n 3 n is null 3 is a text interface that means I'm booting up the text interface.

/etc/inittab The default is only one line in effect: Id:3:initdefault:3 for boot run level 5 for boot into the image interface

Linux boot Process CentOS6