I want to share the home directory off my SS20/Solaris 9 box 
with my oter unix box... including of course my DEC 5000/25 running 
netbsd 1.6.1.  My /etc/dfs/dfstab (in the Solaris 9 box) looks like 
this:

share  -F nfs  -o rw=katri:katrina,anon=-1 -d "Home Dirs"  /export/home

Of course, that was after me playing a bit with the configuration of 
dfstab and screwing most of the time. Since I was using only the DEC 
and the SS20 to test it out, that gave me a bit of a problem in the 
netbsd box (i.e. it mounted but does not let me access it).  So, I 
would like to umount the directory off the netbsd box and put it back 
now that I finally figured out the arguments for share.  Problem is 
that I am having a bit of a problem:

katri# umount -f /home/foo
umount: /home: Permission denied
katri#
katri# df
Filesystem           1K-blocks     Used     Avail Capacity  Mounted on
/dev/sd0a                63639    32546     27911    53%    /
/dev/sd0d               297791   262131     20770    92%    /usr
/dev/sd0e                86686    39390     42961    47%    /home
kushana:/export/home         0        0         0   100%    /home/foo
katri# ls /home/foo
ls: foo: Permission denied
katri#

How can I persuade the partition to properly umount?