[dnanian]

Ah, that's likely because you typed the command incorrectly. It's "LN" in lower case, not "IN". Note that, once you're past the "ln -s" part, you can use "Tab" to complete your typing. And, if there are spaces in a folder name, you need to quote the name or precede the special character with a backslash. So, in your case, it'd be:

ln -s "/Volumes/X Backup/X_Stuff" /X_Stuff

When the command works properly, you should see a symlink appear in the main folder, definitely...

(This wouldn't make you re-clone. If you do it wrong, it'll delete the folder on the destination volume, which is why I requsted that you test first!)