[9fans] Unmount a USB stick?

["devrin talen" <jackfrost13@gmail.com>]

I've got a USB stick that I've been using to shuttle a few docs
around. I googled a bit and I've been using:

% usb/disk -l
% usbfat:

to mount the stick. That works all well and good, but how do I go
about ejecting it gracefully? I've tried:

% unmount /n/usb
% unmount /n/disk

But have no idea if that's the right way to go about it. Additionally
if I eject it in this manner the next time I try to mount it using the
first two commands I get a bunch of usb errors.

Also, why is the disk only available from the rc window that I used to
mount it? In any other rc window I can't access the /n/usb mountpoint.
I realize I'm probably missing something fundamental about plan 9
(newbie here).

- Devrin