7 Types of Linux operating levels

Set the system run level

RunLevel: A state identifier for the Linux runtime that is typically represented by a number,

0 Shutdown Status

1 Single User status (usage: Password loss can be retrieved by entering a single user level)

2 Multi-user state, but no NFS network file system

3 text mode, full command line mode (focus) mode of operation

4 unused system is unused, reserved for use by users

5 graphical desktop mode, X11 (server side does not need to use)

6 Restart Mode

Common operating levels are 3 and 5, to modify the level of the run can be modified in the file/etc/inittab, see the method in 1 to modify the default entry interface.
If set to 0, the boot will shut down, set to 6 will be restarted

Set the run level to (RunLevel) to 3, in fact, is to set the boot with a text command of the Linux management, if you are now the mode of Init 3, there is no need to operate

[[email protected] ~]# runlevelß view Linux current RunLevel

N 3ß indicates that Linux is currently running at 3, which is the text command mode, and the letter N represents the previous run level, which is indicated by default using n if there is no previous runlevel.

#常用级别 3 boot into command line

#常用级别 5 boot into the desktop

Common system operating levels:

Init 5 Switching RunLevel

STARTX switch to graphical interface mode

[[Email protected] ~]# init 6ßinit 6 Run level reboot, also as reboot command

To permanently modify the run level:

Modify the default run level of Linux by modifying the/etc/inittab configuration file.

[Email protected] ~]# Vi/etc/inittab

Id:3:initdefault:

#设置默认加载的运行级别

3 Operating levels of Linux

To resolve the method of modifying the error configuration:

If you are not careful when the operating level is set to 1 or 6 and does not enter the normal Linux, you can follow the following method to solve. (When Grub does not have a password, of course)
(1) Press "E" to enter the Grub boot interface for a few seconds when system boot is in progress
(2) Highlight Select the second line, enter "E" to enter
(3) Enter after entering "1" [single User level] because the single user level does not read the/etc/inittab file at startup
(4) Enter return to GRUB interface
(5) Press "B" to enter single mode
(6) in the single-player mode, follow the 1 inside to modify the/etc/inittab file.
Because the Linux inside the change password do not enter the original password, so if you forget the password can also enter the single-player mode to modify.

7 Types of Linux operating levels