Difference Between Hard Link and Soft Link in Linux

Hard Links

A hard link is a mirror copy of an existing file on a Linux system. In other words, a hard link to a file is a duplicate of the file, sharing the same inode (a data structure that stores file attributes and disk block location(s)).

You can create a hard link using the ln command followed by the source and target files:

ln source_file hard_link

Soft Links

Also known as symbolic links, soft links behave more like shortcuts. They point to the file name and not to the data itself. When the source file's data changes, the soft link reflects this change since it refers to the file's name, not the data.

You can create a soft link with the ln command accompanied by the -s option:

ln -s source_file soft_link

Key Differences

Now that we understand what hard and soft links are, let's explore their key differences:

Referencing: A hard link points directly to the file content, whereas a soft link refers to the file name.

Inode Numbers: Hard links share the same inode number as the original file. In contrast, soft links have a unique inode number.

Linking Across Different File Systems: Hard links cannot span different file systems. On the other hand, soft links can link files across different file systems.

Source File Deletion: If you delete the source file, the hard link still accesses the content because it points to the data. However, if you remove the source file, the soft link breaks because it points to the file name, not the content.

Frequently Asked Questions

What happens to a hard link when the original file is modified?

Since a hard link points to the file content, it reflects the changes made to the original file.

Can a soft link point to a directory?

Yes, a soft link can point to a directory, while a hard link cannot.

What happens when you remove a hard link?

Removing a hard link does not affect the original file or other hard links associated with it.

Conclusion

In summary, understanding hard and soft links is fundamental when working with Linux file systems. They offer flexibility in how files are organized and accessed. Remember that hard links are direct connections to file content and share the same inode as the original file, while soft links are more like shortcuts, pointing to the file name, and not the content.