[Panino]

On OpenBSD, -P overwrites once. It used to be 3, like the author states, but was changed to one pass since multiple overwrites are pointless on mechanical disks. On SSDs you need ~20 passes of the entire drive to remove ~all data, so I doubt 3 passes of a single file on an SSD would accomplish what the person wants.

As an aside, it has never been demonstrated that multiple overwrites improve overwriting. In other words, it's never been demonstrated that data overwritten just once can be recovered. Until that happens I'll agree with other folks that multiple overwrites are a waste of time and electricity, and that FDE is a much more reasonable (not fool-proof, just reasonable) way to make data unavailable to unauthorized persons.