📂 What Is the Linux File System Hierarchy?

Linux follows the Filesystem Hierarchy Standard (FHS) — a guideline that defines how directories should be organized under the root directory /.
This structure keeps Linux systems consistent across distributions and ensures predictable locations for binaries, configs, logs, and user data.

🗂️ Key Directories and Their Roles

Directory	Purpose
/	Root of the entire file system — everything starts here
/bin	Essential user binaries (e.g., `ls`, `cp`, `mv`)
/etc	System configuration files
/var	Variable data like logs, mail, cache, spool files
/home	User home directories (e.g., `/home/rsh`, `/home/alice`)
/usr	Secondary hierarchy: user applications, libraries, documentation
/tmp	Temporary files; often cleared on reboot
/opt	Optional or third-party software packages
/dev	Device files for hardware and virtual devices
/proc	Virtual filesystem with runtime process and kernel data

🧠 Why It Matters

✔ Troubleshooting

Knowing where logs (/var/log) and configs (/etc) reside makes diagnosing system issues faster.

✔ Security

Misplacing files — especially configs or logs — can lead to data exposure.

✔ Automation

Scripts and services rely on consistent directory paths. Understanding FHS ensures reliable automation.

🧰 Pro Tips

Check disk usage in variable directories:

du -sh /var/*
Audit configuration changes with:

ls -l /etc
Avoid putting custom binaries in / or /home — use:
- /opt for optional packages
- /usr/local/bin for custom executable scripts

🚀 What’s Next?

In Post #8, we’ll explore Linux Disk Management — using df, du, mount, and fdisk to inspect, mount, and manage storage devices.

Understanding the Linux File System Hierarchy: /bin, /etc, /var, /home, /usr Explained