>Let me see if I can spell this out.   In the berkeley naming scheme, a
>disk device would be referred to as xxyz, where xx is the device type
>(e.g., sd), y is the unit number (e.g., 0) and z is the partition
>(i.e., a).   The partition numbering is completely unambiguous.

I think the heart of this discussion lies in the fact that the original
example came from NetBSD-Amiga, where, perhaps unlike other NetBSD ports,
the partition letter ('z' in /dev/xxyz) does not correspond in any way
to physical partitions or order in any table. This seems to be unique in
NetBSD-Amiga, always in the past, on other BSD derived systems, your above
statement has been true.