An Introduction to Linux Filesystem Layout: Where Everything Lives
Understand why Linux organizes files differently.
If you're coming from Windows or macOS, Linux’s filesystem might seem confusing at first. Instead of drive letters (like C:\) or neatly hidden system folders, Linux uses a single, unified structure starting from the root directory (/). Everything, from your files to system configurations, branches out from here in a logical (but sometimes overwhelming) way.
This design is built for stability, flexibility, and multi-user support. Need to troubleshoot a crashing service? The logs are in /var/log. Installing software manually? It might go to /opt. Every directory has a purpose and knowing where things live can save you from blind changes.
So, here's everything you should know about the Linux folder structure.
Oyinebiladou Omemu
1. / – Root Directory
This is where the entire filesystem begins. Every file, folder, and device traces back to “/”. Unlike Windows (where “C:\” is one drive and “D:\” is another), Linux treats all storage as branches of “/”. Even if you have multiple hard drives, they’re mounted (attached) to subdirectories here, making everything accessible under one hierarchy.
If you want to see what is in your root directory, run ls / This should show all your directories mounted to the root.
2. /bin & /sbin – Essential System Commands
- /bin holds fundamental tools like ls, cp, rm, bash, grep, mkdir, etc. All the essential commands and utilities every user need, even in emergencies (like when the system can’t fully boot), are in this directory.
- /sbin contains administrative tools like sudo, fdisk, reboot, etc, meant for the root user. Regular users can’t run these by default because they affect the whole system. For instance, if you want to install a system-wide application, you'll need to use sudo, which would require admin authentication.
These directories are split as a security measure. Critical system repairs often require booting into a minimal environment where only /bin is available.
3. /etc – Configuration files
This is where Linux stores configuration files like settings for users, services, and applications. Files like: /etc/passwd (user accounts), /etc/fstab (disk mounts), and /etc/network/ (network settings), stored here.
If you want to check your Linux distro, you can do it from the /etc directory by running "cat /etc/os-release"
Changing a file in the /etc directory can alter how your system behaves. For example, editing /etc/ssh/sshd_config tweaks your SSH server. So, you might want to be very careful with the changes made here.
4. /dev – Device Files
Linux represents every device, from keyboards, disks, even virtual terminals, as files in /dev. For example: /dev/sda (your first hard drive), /dev/null (a "black hole" that discards data), and /dev/random (generates random numbers).
This design lets you interact with hardware using standard file operations. If you need to wipe a USB drive, you could write zeros directly to /dev/sdb.
5. /proc & /sys – Virtual Filesystems
These aren’t real folders, they’re virtual filesystems created on-the-fly by the kernel.
- The /proc directory exposes running processes and system stats. For example, /proc/cpuinfo contains CPU details. And /proc/meminfo contains memory usage.
- The /sys directory provides low-level hardware and kernel settings, like network interfaces, power management controls, etc. You can change or adjust system behavior by editing files here (e.g., adjusting screen brightness in /sys/class/backlight/).
6. /home – Your Personal Files
Each user gets a subdirectory here (e.g., /home/alice). This is where your Documents, Downloads, Application settings, etc., live.
Unlike Windows, Linux strictly separates user files from system files, so you can’t accidentally break the OS by deleting the wrong folder.
7. /tmp – Temporary files
A shared space for temporary files. The files stored here are automatically cleared on reboot. All users can write here (but can’t delete others' files) as well. When you make downloads from web browsers, they are temporarily stored here. When writing files, avoid keeping important files in this directory, as they might vanish.
Oyinebiladou Omemu
Conclusion
The Linux filesystem may seem complicated, but understanding it is essential for knowing how the operating system works. By knowing where files live and why they’re organized the way they are, you can easily play around and make changes in your system.
If you need to troubleshoot a break, you can just check /var/log. If you’re running out of disk space, you can navigate to /home and /var to take a look. This structure is designed for efficiency, security, and flexibility. Once you understand it, you get full control over your chosen operating system.
Image Credit: Oyinebiladou Omemu/techloy.com
