Welcome to Linux Knowledge Base and Tutorial
"The place where you learn linux"
Linux Tracker

 Create an AccountHome | Submit News | Your Account  

Tutorial Menu
Linux Tutorial Home
Table of Contents
Up to --> Files and File Systems

· The EXT2 File System
· The EXT2 Inode
· The EXT2 Superblock
· The EXT2 Group Descriptor
· EXT2 Files
· EXT2 Directories

Man Pages
Linux Topics
Test Your Knowledge

Site Menu
Site Map
Copyright Info
Terms of Use
Privacy Info
Masthead / Impressum
Your Account

Private Messages

News Archive
Submit News
User Articles
Web Links


The Web

Who's Online
There are currently, 150 guest(s) and 0 member(s) that are online.

You are an Anonymous user. You can register for free by clicking here

Linux Tutorial - The Operating System - Files and File Systems - The EXT2 File System - The EXT2 Inode
  The EXT2 File System ---- The EXT2 Superblock  

The EXT2 Inode

Figure 9.2: EXT2 Inode

In the EXT2 file system, the inode is the basic building block; every file and directory in the file system is described by one and only one inode. The EXT2 inodes for each Block Group are kept in the inode table together with a bitmap that allows the system to keep track of allocated and unallocated inodes. The figure above shows the format of an EXT2 inode, amongst other information, it contains the following fields:

This holds two pieces of information; what this inode describes and the permissions that users have to it. For EXT2, an inode can describe one of file, directory, symbolic link, block device, character device or FIFO.
Owner Information
The user and group identifiers of the owners of this file or directory. This allows the file system to correctly allow the right sort of accesses,
The size of the file in bytes,
The time that the inode was created and the last time that it was modified,
Pointers to the blocks that contain the data that this inode is describing. The first twelve are pointers to the physical blocks containing the data described by this inode and the last three pointers contain more and more levels of indirection. For example, the double indirect blocks pointer points at a block of pointers to blocks of pointers to data blocks. This means that files less than or equal to twelve data blocks in length are more quickly accessed than larger files.

You should note that EXT2 inodes can describe special device files. These are not real files but handles that programs can use to access devices. All of the device files in /dev are there to allow programs to access Linux's devices. For example the mount program takes as an argument the device file that it wishes to mount.

 Previous Page
The EXT2 File System
  Back to Top
Table of Contents
Next Page 
The EXT2 Superblock


Test Your Knowledge

User Comments:

You can only add comments if you are logged in.

Copyright 1996-1999 by David Rusling. Licensed under GNU General Public License (Used with permission of the author). See here for details. All rights reserved.
Show your Support for the Linux Tutorial

Purchase one of the products from our new online shop. For each product you purchase, the Linux Tutorial gets a portion of the proceeds to help keep us going.



Security Code
Security Code
Type Security Code

Don't have an account yet? You can create one. As a registered user you have some advantages like theme manager, comments configuration and post comments with your name.

Help if you can!

Amazon Wish List

Did You Know?
You can choose larger fonts by selecting a different themes.


Tell a Friend About Us

Bookmark and Share

Web site powered by PHP-Nuke

Is this information useful? At the very least you can help by spreading the word to your favorite newsgroups, mailing lists and forums.
All logos and trademarks in this site are property of their respective owner. The comments are property of their posters. Articles are the property of their respective owners. Unless otherwise stated in the body of the article, article content (C) 1994-2013 by James Mohr. All rights reserved. The stylized page/paper, as well as the terms "The Linux Tutorial", "The Linux Server Tutorial", "The Linux Knowledge Base and Tutorial" and "The place where you learn Linux" are service marks of James Mohr. All rights reserved.
The Linux Knowledge Base and Tutorial may contain links to sites on the Internet, which are owned and operated by third parties. The Linux Tutorial is not responsible for the content of any such third-party site. By viewing/utilizing this web site, you have agreed to our disclaimer, terms of use and privacy policy. Use of automated download software ("harvesters") such as wget, httrack, etc. causes the site to quickly exceed its bandwidth limitation and are therefore expressly prohibited. For more details on this, take a look here

PHP-Nuke Copyright © 2004 by Francisco Burzi. This is free software, and you may redistribute it under the GPL. PHP-Nuke comes with absolutely no warranty, for details, see the license.
Page Generation: 0.10 Seconds