Overview of Linux File System : Definition, Structure
By Prempal Singh
Linux has been designed right from the start to be multi user and multi task system. In Linux there is just one file system. Media devices like the hard drive, storage or disc and CD-Rom and UNIVERSAL SERIAL BUS(USB) are all mounted collectively in a single directory site or listing structure (e. g. Hard disk is mounted under root (/), CD-Rom is mounted under /media/cdrom). In Windows you simply get the number of partitions (it could be one or more) assigned by characters or correspondence, same apply for CD-Rom and other removable mass media or multimedia like USB thumb drive. Below is the common directories that you will find in many Linux distributions (some might differ slightly).
| File | Description |
| /bin | Standard installed programs like (cp, ls, the good old bash, etc). |
| /boot | Start-up files. |
| /dev | Computer devices considered as files or directories. |
| /etc | Configuration files (for programs). |
| /home | The home directory for all users. |
| /lib | This is where programs shared libraries are stored. |
| /lib64 | This is where 64 bit programs shared libraries are stored. |
| /lost +found | A directory for lost and recovered files due to system errors or crashes. |
| /media | Mounted media like USB flash drive, CD-Rom and cameras. |
| /mnt | Not Properly mounted file systems. |
| /opt | Big third party applications (e.g. oracle, java) reserved for the installation of add-on application software packages. (The equivalent in Windows is Program Files.). |
| /proc
|
A virtual directory that contains processes information like memory usage, mounted devices such as cameras etc. These information are only presentable during run time |
| /root | The home directory for the super user (root). |
| /run | Store files containing run time information during early boot. |
| /sbin | Generally system administration programs like (fdisk, ifconfig,..etc) |
| /selinux
|
A complimentary to a firewall (not a firewall by itself!) it determines which software can access which resources (e.g. forcing apache web server to respond to calls by a previously determined port only). |
| /srv | Holds site specific data that the system provide for protocols like (ftp, www, cvs). |
| /sys | System information is stored in this directory |
| /tmp | A temporary space used by system and programs. It clears its content when the System reboots |
| /usr | Programs, libraries, documentation etc. for all user-related programs. |
| /var | Store all variable files and temporary files (e.g. log files, mail queue, space for temporary Files downloaded from the internet). |
