If the data doesn't matter: Put it on one drive.
If losing the data would cost you minor downtime: Put it on two drives (or storage arrays of some sort) in two locations.
If losing the data would cause major downtime: Put it on three drives (or storage arrays of some sort) in two or three locations.
If losing the data would cause life-disrupting issues for multiple people: Put it on as many drives as possible/feasible (or storage arrays of some sort) in enough locations that you can sleep well at night.
Edit: weird thing to get a bunch of downvotes, but you do what you want with your data