Matching file to a physical medium

[Sad Clouds <cryintothebluesky%googlemail.com@localhost>]

Hi, does anyone know if there is a way to match a file to a particular
physical medium, such as a disk.

With the help of stat(2) I can get st_dev for this file, but st_dev is
unique for each file system, even if those file systems reside on the
same physical disk. What I need is something that can uniquely identify
a physical disk.

Any ideas?