I am not sure if this bug is in VirtualBox or is something deeper.
I mounted a .img file to /media and then tried to share it to the windows xp running in VirtualBox. When I selected the folder VirtualBox crashed meaning it wouldn't respond to anything with the windows window blackened and the shared folder window also dead. I had to kill all processes linked with VirtualBox from the terminal and when the VirtualBox was zombified I still couldn't get rid of the VirtualBox opened windows. So I tried xkill to kill the opened windows since (theoretically) everything associated with VirtualBox was dead. xkill did the trick and everything closed. Then I went to the mount point with nautilus and when I clicked to open the folder nautilus froze with Uninterruptible trying to do I/O on the folder I guess. From what I read it is impossible to kill an Uninterruptible process so I tried to unmount the mounted .img but it said the device is busy. I finally manage to unmount by using umount -l trying to force some exception in the I/O in the kernel but still nothing, nautilus is Uninterruptible. I tried to remount the folder but I couldn't since it said it's busy, so now I am stuck with an open nautilus process that cannot be killed!
I do not know whether this is a VirtualBox bug, a mount bug, a nautilus bug or a kernel bug! Any help killing nautilus is appreciated since rebooting is not an option!
Also running ps aux | grep nautilus I get
user 23726 0.2 0.0 738636 1296 ? D Feb26 27:59 /usr/bin/nautilus
Doesn't this mean that nautilus is Defunct? So why am I getting Uninterruptible in System Monitor?
ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: virtualbox-qt 4.1.2-dfsg-1ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic i686
NonfreeKernelModules: fglrx
ApportVersion: 1.23-0ubuntu4
Architecture: i386
Date: Tue Mar 6 12:25:49 2012
ExecutablePath: /usr/lib/virtualbox/VirtualBox
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
ProcEnviron:
LANGUAGE=en
PATH=(custom, no user)
LANG=en_US.utf8
SHELL=/bin/bash
SourcePackage: virtualbox
UpgradeStatus: Upgraded to oneiric on 2011-10-14 (144 days ago)
Status changed to 'Confirmed' because the bug affects multiple users.