Snoop de dupe is a fully featured file de-duplication software tool which will automatically scan for duplicate files anywhere on your server and easily allow you to delete, keep, or hard-link duplicate files to conserve, and optimize, your hard disk storage.
Keep your server’s storage space optimized! Snoop-de-dupe will automatically scan your server storage in real-time and display duplicate files in an easy-to-view layout directly within the server’s user Console. Once snoop-de-dupe locates duplicate files then you can respond to them as you choose. You can delete the duplicate files, ignore/keep the duplicate files, or replace the duplicate files with a hard-link (available in WHS/SBS 2011 and Server 2012 Essentials only). You will be in command of your server storage space like never before!
You can find many tutorials and how-to write-ups on this support blog to see how Snoop de dupe can work for you