I don’t think you need to delete the partitions separately, since it’s just a table at the very beginning of which parts of the disk belong to which partition?

So if you dd zeroes over everything, the first thing that gets deleted is the partitioning table

I might be wrong here, or maybe it doesn’t apply to every situation, but that’s how I’ve understood it to work

Also a tip for OP: don’t write zeroes over it, but random data (dd if=/dev/urandom ...). It’s a bit more secure as it makes it harder to see the size and location of the encrypted data on the disk

Says the one who hasn’t yet had an aeroplane crash into their house

https://knowyourmeme.com/memes/twisted-fucking-cycle-path