public/reallycleandisk.sh

#!/usr/bin/bash 
set -x

DISK=${1:-nodisk}

if [ "x${DISK}" = "xnodisk" ]; then
  echo "What disk ? (sda, sdb, nvme0n1,...)"
  exit 1
fi

SIZE=$(sudo blockdev --getsz /dev/${DISK})
PBSZ=$(sudo blockdev --getpbsz /dev/${DISK})
SEEK=$(($SIZE - 256 * 1024 * 2 / $PBSZ)) 
LEN=$((256 *2 *1024 /$PBSZ))	
# SEEK=$(( $(sudo blockdev --getsz "/dev/sdX1") -  256 * 1024 * 2 / $(sudo blockdev --getpbsz "/dev/sdX1")))
echo $SIZE $PBSZ $SEEK $LEN
for i in 1 2 3 4 ; do
  TOWIPE=${DISK}${i}
  if [ -b /dev/$TOWIPE ] ; then
    sudo wipefs -a -f /dev/${TOWIPE}
    sudo  dd if=/dev/zero of=/dev/${TOWIPE} bs=$PBSZ count=$LEN 
    sudo  dd if=/dev/zero of=/dev/${TOWIPE} seek=$SEEK bs=$PBSZ count=$LEN 
  fi
done



sudo wipefs -a -f /dev/${DISK}
sudo  dd if=/dev/zero of=/dev/${DISK} bs=$PBSZ count=$LEN 
sudo  dd if=/dev/zero of=/dev/${DISK} seek=$SEEK bs=$PBSZ count=$LEN