Sir, kindly guide me Why My more than 500 GB data Deleted automatically from my 2nd installed 2TB HDD Drive. When I opened my MacBook Pro I was surprised that judge amount of my files deleted automatically. And How can I recover all of those data free of cost.
These are the Developer Forums, where developers of apps for Apple's platforms ask each other for hints and tips on coding.
Your question is more of a product support one, so I'd suggest you ask it over at the Apple Support Forums. Thanks.
(Also, you should explain in a little more detail what exactly has happened. Is this an external HDD? What happened when you booted the MacBook Pro? What data has been deleted?)