On Wed, Jan 20, 2010 at 2:10 AM, David Relson <relson@osagesoftware.com> wrote:
I've been using VirtualBox recently with 32-bit Ubuntu for a work
project. It seems that whenever my thumb drive is moved between host and
guest operating system, Gentoo is mounts it as a new device (see
below).  Can these extra device mounts be avoided?

Regards,

David

 
osage relson # df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1              99M   17M   78M  18% /boot
/dev/sda4             437G  226G  189G  55% /
/dev/sdb1             466G  259G  208G  56% /mnt/usbhd
/dev/sdc              7.5G  2.7G  4.8G  36% /mnt/usbkey
/dev/sdd              7.5G  2.7G  4.8G  36% /mnt/usbkey
/dev/sde              7.5G  2.7G  4.8G  36% /mnt/usbkey
/dev/sdf              7.5G  2.7G  4.8G  36% /mnt/usbkey
/dev/sdg              7.5G  2.7G  4.8G  36% /mnt/usbkey
/dev/sdh              7.5G  2.7G  4.8G  36% /mnt/usbkey
/dev/sdi              7.5G  2.7G  4.8G  36% /mnt/usbkey
/dev/sdj              7.5G  2.7G  4.8G  36% /mnt/usbkey
/dev/sdk              7.5G  2.7G  4.8G  36% /mnt/usbkey

This doesn't happen with me. I'm using the binary version of virtualbox. When I plug the pen drive on Gentoo, it mount it for my host usage. When I go to the virtualbox menu usb devices and mark the checkbox for my pen drive, the pen drive is unmounted on the host and mounted on the guest (btw, Windows XP). The inverse process occurs when a uncheck the usb on the virtualbox usb devices menu.

Guess, are you using the open source of virtualboxes ? I think there are difference in the usb usability betweek binary and open source version.