Even genomics isn't really that big. The human genome is three billion base pairs; that's 750 MB if packed as tightly as can be. The largest genome (that of _Paris japonica_) is 150 billion base pairs, 37.5 GB.

You might be storing multiples of that amount of data if you are doing a shotgun sequence assembly, or looking at polymorphisms, but then you're likely to have no more than 10 copies, and i can't imagine you'd have more than 100 copies. For the human genome, 100 copies would be 75 GB, which is still only about four times the size of Team Fortress 2.