>> Further, the serial number is almost never associated with the
>> actual media, but with the physical device.  This means that the
>> serial number you get back is usually worthless for removable
>> media devices.  You really need to tag the media if you want to make
>> this work.
>
>Absolutely, but there are a number of non-removable USB disk available.
>As for removable ones I'm sure you could come up with some "fingerprint"
>from the superblock.

"fingerprinting" works for fixed media devices too, so why not just rely
on it instead of adding two different identification schemes?

--
Justin