[SOLVED] How do I completely erase a hard drive so I can sell it?

[jm88]

I have a couple of large external backup drives that I don't use so I may as well sell them. What is a good way to complete erase them so they are not recoverable?

 

[USAFRet]

For HDD, DBAN.

For SSD, the Secure Erase function from the manufacturer.