unmounting a volume

[Jonathan Hutchins]

I was trying to test four modems on a USB Serial Adaptor Friday by using
minicom, and had a number of problems that caused minicom to lock up.  For
some reason, one instance locked and could not be killed, maintaining a
lock on the port and occupying the VC it was running on.  I eventually
rebooted to correct it.

(I eventually figured out that minicom would only address /dev/usb/tts/0,
no matter which port I set it to in it's config file.)