There are hdd mineable coins that are produced that can earn you cryptocurrency with a proof of storage algorithm.
Two of the most common work in this way:
Burst Coin - uses data plots on a hard drive in order to prove the capacity of the hard drive, the person/pool with the highest capacity wins.
Storj - sells your hard drive storage online and allows you to download what someone else wants to store onto it and rent it out that way.
Don't expect to earn very much though unless you have a large amount of stoarge.