Hard Link vs Symbolic Link in Ubuntu: Main Differences

In Ubuntu, both hard links and symbolic links allow users to access files through multiple names, but they function differently at the filesystem level. This article outlines the core distinctions between these link types, including how they handle inodes, directory restrictions, and what happens when the original file is removed. Understanding these differences helps you choose the right linking method for backups, shortcuts, or system organization.

What Is a Hard Link?

A hard link is a direct reference to the specific location of data on the disk, known as the inode. When you create a hard link, you are essentially creating another name for the exact same file data. The filesystem does not distinguish between the original filename and the hard link; both are equal entries pointing to the same underlying data.

What Is a Symbolic Link?

A symbolic link, often called a symlink or soft link, is a special type of file that contains a path to another file or directory. It acts like a shortcut in Windows or an alias in macOS. The symlink has its own inode and simply points to the location of the target file rather than the data itself.

Key Differences

• Inode Usage: A hard link shares the same inode number as the original file. A symbolic link has a different inode number.
• Filesystem Boundaries: Hard links cannot cross filesystem boundaries (e.g., linking a file from your hard drive to a USB stick). Symbolic links can cross filesystems and partitions.
• Directories: You cannot create a hard link to a directory in Ubuntu. Symbolic links can point to directories.
• File Deletion: If the original file is deleted, a hard link remains accessible because the data persists until all links are removed. If the original file is deleted, a symbolic link becomes broken and unusable.
• Size: A hard link does not consume additional disk space for data storage. A symbolic link consumes a small amount of space to store the path string.

How to Create Links in Ubuntu

You create both link types using the ln command in the terminal.

To create a hard link:

ln source_file hard_link_name

To create a symbolic link:

ln -s source_file symbolic_link_name

When to Use Each

Use hard links when you need multiple names for a file within the same partition and want to ensure data persists even if one name is deleted. This is common for backup strategies within a single drive. Use symbolic links when you need to link across different drives, link to directories, or create shortcuts that users can easily identify as links.