> I would have expected that trying to mount something on a directory
> already in use as a mount point would have given an error.  It doesn't
> on either 1.0/i386 or -current/i386.

This is a 4.4 feature -- stackable mounts. There was a paper about it
in the Winter 1995 Usenix.

It's annoying, though, when I edit fstab and do mount -a, in which
case it remounts multiple instances of some of the file systems. It
perhaps should avoid mounting the _same_ file system twice on the same
mount point.

--
Trevor Blackwell         tlb@eecs.harvard.edu          (617) 495-8912