Linux Filesystem Basics

1. Introduction

The Linux filesystem is a hierarchical structure that organizes files and directories. Understanding this structure is crucial for effective navigation and management of a Linux system.

2. Filesystem Structure

2.1 Hierarchical Layout

Linux organizes files in a tree-like structure starting from the root directory /. Key directories include:

/bin: Essential user binaries
/etc: Configuration files
/home: User home directories
/var: Variable files (e.g., logs)
/usr: User programs

Note: Always navigate using absolute paths (e.g., /etc/hosts) to avoid confusion.

3. Common Commands

3.1 Navigation Commands

To navigate the filesystem, you can use the following commands:

cd /path/to/directory    # Change directory
ls -l                     # List files in long format
pwd                       # Print working directory

4. File Permissions

Understanding file permissions is essential for security. Each file or directory has three types of permissions:

Read (r)
Write (w)
Execute (x)

These permissions can be set for three different user classes:

Owner
Group
Others

To view permissions, use:

ls -l

To change permissions, use:

chmod 755 filename

5. Best Practices

When managing filesystems in Linux, consider the following best practices:

Use meaningful directory names.
Regularly back up important data.
Monitor disk usage to avoid running out of space.
Set appropriate permissions for security.
Document your filesystem structure for future reference.

6. FAQ

What is the root directory?

The root directory is the top-level directory in a Linux filesystem, denoted by /.

How can I check disk space?

You can check disk space using the command df -h.

What does chmod do?

The chmod command changes the file permissions for files and directories.