Comment by SoftTalker
8 hours ago
All you really need to do is write one pass of zeros on them. That will prevent anyone but a very dedicated adversary with expensive equipment from recovering any data, especially on TB scale drives.
Can still take hours per drive though, which is why a lot of people skip it.
Or encrypt it and just trash the encryption header.
I make a random 1MB chunk, then write that all over the drive, at overlapping offsets. I've been told that really clears it. On IDE-spinning-rust disks I trusted it, not sure if I should trust these modern SSD
Why rewrite the same 1MB chunk, instead of making new random chunks?
Redundant data at least opens the possibility that the drive could deduplicate.
Cause making new random was taking too much time.