Linux Remove All Partitions / Data And Create Empty Disk

How do I remove all partitions, data and create clean empty hard disk under Linux operating systems?

The simplest command to remove everything from Linux hard drive is as follows. Please note that this will remove all data so be careful:

dd if=/dev/zero of=/dev/hdX  bs=512  count=1

OR for sata disk, use the following syntax:

dd if=/dev/zero of=/dev/sdX  bs=512  count=1

In this example, empty sata disk /dev/sdb, enter (you must be login as the root user):

fdisk /dev/sdb
dd if=/dev/zero of=/dev/sdb  bs=512  count=1
fdisk -l /dev/sdb

Securely Wipe Hard Disk

You can use the shred command to securely remove everything so that no one recover any data:
shred -n 5 -vz /dev/sda