[Sussex] Really Dumb dd question

[Nik Butler]

The purpose of this exercise is to make a exact ( partition is not an
issue here ) duplicate of a disk which can be swapped from hdc to hda in
the cables should hda collapse.. we can then if hda is still functional
swap the disks around and walk away. the customer has a near instant
last night replacement. just a shortcut to resolving problems.

 so how would cpio do this better ?