Linux File Systems

In Linux, file system begins with root (/). This is at the top of the file system which means it is the starting point directory structure . Under root (/) there exists other files/folders.

Important Directories

Home Directory

/root

This is the root's home directory ie superuser's home directory.

/home/username

This is a directory in Linux system where each user a special directory. This is the default location when the user logs into the system. Eg: If a user of the system is called student, the home directory of tom will be /home/student

User Executables

/bin

This directory contains the most important programs that the system needs to operate, such as the shells, ls, grep, and other essential things.

/usr/bin

This directory contains applications for the system's users. Utilities like compilers, firefox browser and openoffice go into /usr/bin.

/usr/local/bin

Common executable application files ie software compared from source code goes here

In some cases it really doesn't make much difference if you put the program in /bin or /usr/bin .

System Executables

/sbin, /usr/sbin

This is where system programs are installed.  Most system administration programs are stored in these directories. You must run these programs as the root user. These include fdisk, tools to make partitions, certain network tools, etc

Mountpoints

The different physical storage devices  must be attached to some directory in the file system tree before they can be accessed. This attaching is called mounting, and the directory where the device is attached is called the mount point.

/mnt

Filesystems that are non-removable media will be mounted here

Eg:harddisk

/media

Filesystems that are removable media will be mounted here

Eg:cdrom

Configuration

/etc

The configuration files are stored in this directory .In /etc/ we can find the system's password file, group lists, user skeletons, cron jobs etc.

Temporary files

/tmp

This is the default location to place files for temporary use. When you install a program, it uses /tmp/ to put files during installation that won't be needed once the program is installed. The /tmp directory allows all users access to additional space to meet short term needs without charging the space against their quota. All files placed in this directory are deleted automatically after a few days.

Bootloader

/boot

This is the directory where Linux keeps information that it needs when booting up.

Server Data

/var

This contains administrative files such as log files, locks, spool files, and temporary files used by various utilities

/srv

This contains server data's such as databases and webpages

System Information

/proc

This is a virtual directory which contains information about the kernel. It doesn't contain 'real' files but runtime system information.

/sys

This gives information about hardware

Shared Libraries

/lib, /usr/lib

Important system libraries are stored here.