This document provides an overview of the Linux filesystem, including its structure, key directories, and concepts like mounting. It describes the Filesystem Hierarchy Standard which defines the main directories and their contents. Key points covered include that everything in Linux is treated as a file, the top-level root directory is "/", essential directories like /bin, /dev, /etc, /home, /lib, /proc, /sbin, /usr, /var are explained, and mounting additional filesystems is described.

1. ‫آموزش‬ ‫دپارتمان‬
‫لینوکس‬ ‫آموزش‬

2. GNU/Linux Filesystem
Mohammad Reza Gerami
mrgerami@aut.ac.ir
gerami@aryatadbir.com

3. 3
What We Will Learn
Introduction
Filesystem Hierarchy Standard
Directory layout of Linux FS
Help
Mounting

4. 4
Introduction
 Filesystem
 How are data stored in storage?
 How do users access the data?
 Data organization, files and directories
 Filesystem types
 Disk FS: ext2, ext3, FAT, FAT32 & NTFS
 Network FS: Samba & NFS
 Flash FS: JFFS2
 Special FS: proc FS

5. 5
Introduction (cont’d)
 You should understand Linux FS
 Why?
 Everything in Linux is file, if it is NOT process
 Easy to use
 Open file, read/write and close the file
 Unlike Windows, Linux FS is standard FS
 Everyone should learn standards

6. 6
Filesystem Hierarchy Standard
 Started by Dennis Ritchie, 1993
 Defines the main directories and their contents in
most Linux-based systems
 Current Version: 2.3.

7. 7
FHS
 There is not any drive C:, D:, …
 All directories are under “/”
 “/” is the root directory
 It is possible
 to have multiple partitions
 to multiple filesystems

8. 8
The “/”
 The primary hierarchy in FSH
 The root of tree of filesystem
 All paths start form here
 There is only one “/” in filesystem

9. 9
The “/”
/
boot bin dev etc lib proc root sbin tmp usr var

10. 10
boot
 Linux kernel
 Boot loader configuration
 If you lost boot
 You cannot boot your OS

11. 11
boot
boot
vmlinuz-2.6.12 config-2.6.12 grub
grub.conf

12. 12
bin
 Essential programs
 Need for system startup
 Basic commands for
 Navigating in filesystem
 File management

13. 13
bin
bin
bash bzip2 cat gzip ls mv rm...

14. 14
dev
 Everything is file
 Hardware components (devices) are file
 Hard disk
 Key board
 All device files are here
 Direct interaction with device driver
 Open the device file
 Read & Write

15. 15
dev
dev
hda fda sda tty random null...

16. 16
etc
 System configuration directory
 What is done by the registry in Windows
 All configuration file are text files
 You can view and edit it manually

17. 17
etc
etc
bashrc fstab inittab passwd shadow X11
X11.conf
init.d
network named httpd

18. 18
home
 Home directory of user
 Each user has a directory
 /home/bahador
 /home/hamed
 All files of user are stored here

19. 19
lib
 Programs need libraries
 Dynamically linked libraries
 Programmers need libraries
 All essential libraries are here
 Needed for system startup

20. 20
lib
lib
libc libm libcrypt libpthread modules

21. 21
proc
 Kernel’s interface
 Kernel pseudo-directory
 Special directory
 It is NOT a directory on hard disk
 Kernel Configuration
 Kernel State monitoring

22. 22
proc
proc
cpuinfo meminfo devices interrupts net sys
tcp udp kernelnet
1 129

23. 23
root
 Home directory of root
 Don’t confuse
 / is the “root of Filesystem”
 root is the name of system admin
 /root is the admin

24. 24
sbin
 System configuration programs
 Format hard disk
 Manage hardware
 Only “root” can run the programs

25. 25
sbin
sbin
fsck mkfs mount adduser poweroff...

26. 26
tmp
 Temporary directory
 All temp files are created by programs
 Your temp files
 It is emptied regularly

27. 27
usr
 Secondary hierarchy
 Very useful programs
 We usually use them
 compiler, tools
 Are not essential for system startup

28. 28
usr
usr
bin doc include lib local sbin src
Linux-2.6.14

29. 29
var
 The variable directory
 All dynamic files
 User cannot change the files

30. 30
var
var
cache lib lock log www named
message boot.log

31. 31
Helps
 Some documents are in /usr/share/doc
 Info pages are not complete help
 info <command name>
 Man pages
 /usr/share/man
 man1: user commands, man8: System administration
 man <command name>

32. 32
Permissions
 There are 3 basic permissions
 Read (r)
 Write (w)
 Execute (x)
 How to find them
 ls -l
 How to change them
 chmod +/- r/w/x <filename>

33. 33
Mounting
 Mount
 To add a filesystem to other filesystem
 Add you cool-disk FS to you laptop FS
 How?
 mount <options> <device> <mount point>
 mount -t vfat /dev/sdb1 /mnt/flash
 Don’t forget the umount
 umount <mount point>
 umount /mnt/flash

34. 34
Linux FS vs. Windows FS
 There is not drive C:, D:
 Top hierarchy is /
 Path separator is / not
 File extensions have NOT any meaning
 There is not hidden attribute, hidden files are
started by .

35. 35
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