I need to erase all partitions stored on second hard disk. Let us name it /dev/sdb. That is actual name of my second disk and it comes with two Linux partitions
/dev/sdb1
/dev/sdb2
How do you delete and erase all Linux partitions from /dev/sdb and make it empty like a brand new disk?
The only certain way to permanently remove all partitions/data from a disk is to physically destroy the disk. However, since the OP is discarding their system it appears that there is no particular desire to reuse the disk.
If you want to reuse the disk, just repartition as necessary.
@axisofevil I don’t want to physically destroy my hard disk. I never typed I want to. I want to remove all old data and make it like new as I did using dd command. That is the correct answer for me at least.