Sign in Subscribe
Linux+

Understanding Symbolic and Hard Links in Linux

This post explains the difference between symbolic and hard links in Linux, how to create each type using the ln command, and when to use one over the other. It covers key concepts like inodes, cross-filesystem limitations, and what happens when the original file is deleted.

Jay Whale

• 3 min read
Understanding Symbolic and Hard Links in Linux

When you're managing files on a Linux system, you'll quickly discover that a file doesn't always have to live in just one place. Linux gives you two powerful tools for creating references to files: symbolic links and hard links. Understanding the difference between them will save you from confusion and help you make smarter decisions when organizing your filesystem.

Before diving into the comparison, it helps to understand how Linux thinks about files. Every file on a Linux system has an inode, which is a data structure that stores metadata about the file (permissions, ownership, timestamps, and the location of the actual data on disk). The filename you see in a directory is really just a pointer to that inode. Links take advantage of this relationship.

A hard link creates an additional directory entry that points directly to the same inode as the original file. Think of it as giving the same file a second (or third) name. Both the original file and the hard link are completely equal, and there is no way to tell which one came first.

To create a hard link, use the ln command:

ln original.txt hardlink.txt

You can verify they share the same inode with ls -li:

$ ls -li
2883587 -rw-r--r-- 2 user user 42 Jun 10 09:00 hardlink.txt
2883587 -rw-r--r-- 2 user user 42 Jun 10 09:00 original.txt

Notice the inode number (2883587) is identical for both entries, and the link count shows 2. Key things to know about hard links:

  • Same filesystem only: Hard links cannot span across different filesystems or partitions.
  • Files only: You cannot create a hard link to a directory (to prevent filesystem loops).
  • Survives deletion: If you delete the original file, the hard link still works because the inode and data remain as long as at least one link points to them.

A symbolic link (also called a symlink or soft link) is more like a shortcut. It creates a new file that simply contains the path to the target file. The symlink points to a filename, not directly to an inode.

To create a symbolic link, add the -s flag:

ln -s original.txt symlink.txt

Running ls -li shows a very different picture:

$ ls -li
2883587 -rw-r--r-- 1 user user   42 Jun 10 09:00 original.txt
2883592 lrwxrwxrwx 1 user user   12 Jun 10 09:15 symlink.txt -> original.txt

Notice the symlink has its own inode number and the l file type indicator. Key things to know about symbolic links:

  • Cross-filesystem support: Symlinks can point to files on different filesystems or even network paths.
  • Works with directories: You can create a symlink to a directory, which is something you cannot do with a hard link.
  • Breaks if target is deleted: If the original file is removed, the symlink becomes a "dangling" or broken link and will return an error when accessed.
  • Easier to identify: You can always spot a symlink with ls -l because it shows the -> arrow pointing to its target.
  • Inode: Hard links share the original inode; symlinks have their own inode.
  • Cross-filesystem: Hard links cannot cross filesystems; symlinks can.
  • Directories: Hard links are not allowed on directories; symlinks are.
  • Original deleted: Hard links remain valid; symlinks break.

When to Use Each

Use a hard link when you need a reliable, persistent reference to a file within the same filesystem and want the data to survive even if the original path is removed. Use a symbolic link when you need flexibility, such as linking across filesystems, linking to directories, or creating shortcuts that are easy to identify and manage.

In day-to-day Linux administration, symbolic links are far more common. You'll see them constantly in places like /etc/alternatives and when linking configuration files in deployment workflows.

What's Next

Now that you understand how Linux links work, the next logical step is exploring file permissions and ownership in more depth. Knowing who can read, write, or execute a file (and how to change those settings) is a core skill covered in the same exam domain and essential for any Linux administrator.

🔧
Dangling symlinks can cause subtle issues that are hard to track down manually. Tools like the 'symlinks' utility or a quick 'find / -xtype l' command can scan your filesystem and surface broken links before they cause problems in production. find (with -xtype l), symlinks utility and lsof.

Tools and resources for this topic