Linux – Wipe Disk with dd command
Wipe Entire Disk
dd if=/dev/zero of=/dev/sda bs=1M
Or
dd if=/dev/urandom of=/dev/sda bs=1M
Wipe MBR
dd if=/dev/zero of=/dev/sda bs=446
dd if=/dev/zero of=/dev/sda bs=1M
Or
dd if=/dev/urandom of=/dev/sda bs=1M
dd if=/dev/zero of=/dev/sda bs=446