You need to create a hard link to a directory or a file
You can create a hard link with the command ln:
ln ExistingFile TheHardLink
You cannot create hard links for directories, only for files!
Hard links can only be create on the same filesystem and have the same inode. A reference counter can be seen with ls -la. Only when the last link has been deleted the file and the inode will be deleted.
Please note that a hard link is not the same as a symbolic link. A symolic link can be used on files and directories, can be used on differen filesystems and can be "dead" (have no reference anymore).
About the Author
Wim Peeters is electronics engineer with an additional master in IT and over 30 years of experience including time spent in support, development, consulting, training and database administration. Wim has worked with SQL Server since version 6.5. He has developed in C/C++, Java and C# on Windows and Linux in different European countries and different European languages. He writes knowledge base articles to solve IT problems and publishes them on the Lubby Knowledge Platform where he is one of the most important contributors and the main developer.