How did you mount the device? I get unmount issues with usb file devices with some regularity. I have closed all file managers, and terminals I've had open with varying success. Generally, logging out of KDE and back in does it for me. Some bug in kfilemanager perhaps? I've never had a command line hang as a result of this though. I have also used ctrl-alt-bspace to kill X entirely, and all it's real and imagined processes. Either of these techniques has always worked for me. It is a bit extreme, if you ask me (even a bit Microsftesque). Still it's better than rebooting, or walking the process tree. Also you might try looking at ps and using the option to display the child/parent relationship, but if the problem is similar to mine this won't help.
Brian Densmore
-----Original Message----- From: Duane Attaway
What do you do when you want to unmount a volume, but its BUSY by some nonexistant process?
I had a USB drive mounted and the drive went into suspend. It doesn't wake up properly with this kernel and unmounting hangs the command line. Syncing hangs too. Unmounting with the -f option tells me umount is also busy?!