To Understand the architecture of Linux based operating systems.

Let start the learning and understand of file system.

/
system root directory. first major section of file system

/boot
boot file, kernel etc

/dev
contains special/device files like /dev/zero, /dev/null, /dev/tty

/etc
configuration files

/home
user home directory. For example “nitin” user will have /home/nitin, “anshika” user will have /home/anshika
directory

/root
root user’s home directory.

/media
mount point for removable media such as dvd, cdrom, usb drive

/mnt
temporarily mounted filesystems.

/selinux
contains security enhanced linux filesystem

/opt
installing additional software. suppose you wan to install “oracle”, it should be installed here.

/proc
Virtual file system. It holds memory, process, kernel information

/bin
essential binaries available to all users i.e root as well as normal users like “ls”, “mv”, “cp”, “date” etc

/sbin
essential system binaries available to root only such as “fdisk”, “mount” etc

/usr/bin
non essential binaries available to all users such as “passwd”

/usr/sbin
non essential system binaries available to root only such as “useradd”, “userdel”, “usermod”.

/usr/local/bin
non essential binaries available to all users by locally installed packages

/usr/local/sbin
non essential system binaries available to root user by locally installed packages

/lib
essential libraries for the binaries in /bin/ and /sbin

/usr/lib
libraries for the binaries in /usr/bin/ and /usr/sbin/.

/srv
site-specific data which is served by the system.

/tmp
Temporary files often lost during reboot

/var/tmp
temporary files to be preserved between reboots.

/var/yp
holds NIS database

/usr
read only user data. second major section of filesystem

/usr/local
local hierarchy. third major section of file system

/usr/include
standard include files.

/usr/share
architecture-independent data.

/usr/share/doc
documentation

/usr/share/man
manual pages ie when we run command “man ls” it picks information from this directory.

/usr/share/dict
words used in system

/usr/src
source code

/etc/X11
configuration for X windows system

/var
for files where data is continuously changing such as logs, spool files, and temporary e-mail files. the data for
apache web server is kept in “/var/www/html” & for vsftpd ftp server in “/var/ftp/pub”

/var/lock
lock files. Files keeping track of resources currently in use.

/var/log
various log files

/var/mail
contains user mailboxes

/var/run
Information about the running system since last boot, e.g., currently logged-in users and running daemons.

/var/spool
spool for tasks waiting to be processed, e.g., print queues and unread mail.

We’ve seen architecture of linux file system and also whats the use of directories and file system.