How can I tell which users are making a mounted dev "busy"

[BARBOUR JIM]

I am trying to write write a program (or script) which will alert persons
on NFS filesystems served by my machine that the machine is being shut down.

I don't need to worry about which machines are being served since we only export
to one other machine.

However, I have not been able to figure out a way of determining who is
"using" a given file system.  This could be anything from sitting in an nfs
directory, to running a program on an nfs directory, to catting a file.

Any suggestions would be greatly appreciated. You may post or mail responses to:

	barbour at spot.Colorado.EDU

Jim Barbour - Student Systems Administrator - University of Colorado at Boulder