Learn the Linux system from scratch (i)

Source: Internet
Author: User

Linux system: Time-sharing multi-user multi-tasking operating system;

Linux system Boot process:

In the Inittab configuration file:

Defines the 7 levels of the operation of the Linux system: from 0~6

0, 6: On behalf of the shutdown and restart, is not recommended to set the default operating level, otherwise the system will not work properly;

4: Not used, left to users to customize the use;

1: Single-user mode, only administrators can use;

2, 3: No graphical interface, 2 less than 3 NFS (network File system, a security hidden network sharing service)

5: With graphical interface

To view the current RunLevel: # RunLevel Pre-level current level

Toggle RunLevel: Init/telinit [0123456Ss] SS is represented as RunLevel 1

Inittab configuration file Content format:

To define a process record:

ID (2-bit identifier): Run-levels (Run level): Action (Running State): Process (script and command to run)

Action Value:

Initdefalut (default value)

Sysinit (regardless of the runlevel, as long as the system executes once)

Wait: Executes the instruction in the process, and so on after it finishes running other commands

Once: Executes the instruction in the process without ending it (not used)

Executes the command specified by the process when Ctrlaltdel:ctrl+alt+del (the default is the shutdown directive) = = = That's why the Power Bar shortcut key is the origin of the shutdown Dafa

Note: The start script location of action Sysinit is in: sysint/ect/rc.d/rc.sysinit

Then you will determine the operating level of the system, to find a different RunLevel startup script directory, by viewing the file: s start, the beginning of K to stop, the smaller the priority is higher; You can modify the file name to achieve the purpose of not allowing the system to start certain services; for example: RunLevel 3 directory/etc/rc.d/ RC3.D or/ETC/RC3.D

Ctrl + ALT + F1~F6: Start 6 terminal F7: Back to the original page

Note: If the command does not make it possible to conflict with the shortcut keys in the virtual machine, you need to change the shortcut keys for the virtual machine;

Learn the Linux system from scratch (i)

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.