Thanks to everyone for the suggestions.  The problem is both more and less
mysterious than I thought:  if I type everything on a mount command then it
works just fine.  If I take the output of mount -p and put it in
/etc/vfstab (on the Solaris box) then mount /mirror just hangs.

I guess I'll have to find a Solaris guru.

Signature failed Preliminary Design Review.
Feasibility of a new signature is currently being evaluated.
h.b.hotz@jpl.nasa.gov, or hbhotz@oxy.edu