We've had a problem come up the odd time where we are going to reboot
the server and one NSS volume won't umount. We see "device is busy"

It's a 250 gig nss volume. It doesn't happen often but when it does it causes problems. I've waited up to 30 mins and it still hasn't been umount. I believe
it due to open files on the volume. Is there a ncpcon command that will force all files to close and will the umount -f command force a NSS volume to umount no matter what. We are running OES V1.