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 (or storage arrays of some sort) in enough locations that you can sleep well at night.