How to wipe all data without the possibility of recovery from a hard drive?

Question

Hard disks

How to erase all data so that later it would be impossible to recover any information. There is only Ubuntu installed on the hard drive itself. And on the flash drive there is a version 16 recorded from the official distribution.

Answer 1

dd if= /dev/zero of=/dev/sda

Answer 2

Under Windows there is a utility file shredder 2.0 there is an American standard for overwriting data in 3 passes.
If it doesn’t matter to you whether the hard drive survives, then during operation ... start copying something there, take the disk in your hand and slap it with your palm from above, 5-6 times ... the heads cut furrows on pancakes, it becomes very difficult))))