Overview

This post summarizes the differences between symbolic links and hard links.

Prerequisites

• inode
  • Data structure
  • Holds attribute information on the file system (creator, group, creation date, etc.) as data
  • You can check the inode number with ls -i1 / or stat /

What is a Symbolic Link?

• Adds a directory entry that references the path of the original file or directory
• Experiment

touch a.md
ln -s a.md a_symbolic_link.md // Create a symbolic link
ls -i1 a.md a_symbolic_link.md // You can confirm that the inodes are different

• Cannot be referenced if the original file is moved
• Deleted if the original file is deleted
• Can be referenced across different file systems

What is a Hard Link?

• Adds a directory entry that references the inode of the original file or directory
• Experiment

touch a.md
ln a.md a_hardlink.md // Set a hard link
ls -i1 a.md a_hardlink.md // You can confirm that the inodes are the same

• No effect if the original file is moved
• Not deleted if the original file is deleted
• Can only be referenced within the same file system

References

• Differences Between Symbolic Links and Hard Links
• Practical Linux System Administration