In message <Pine.NEB.4.51.0303172135590.722@lothlorien.starwolf.com>, Greywolf 
writes:
>One used to be able to run df on an unmounted fs, accessing it via
>the block (or was it the char?) special device, showing no mount point
>associated with it, but giving the correct stats for the filesystem
>in question.

You could?  That's weird.  I would have expected to get the df stats for
the nearest enclosing filesystem, same as for any other file.

-s