April 21, 2010
On my Centos 5.4 I installed Virtualbox and run Windows XP guest OS on it. After installation it showed available USB devices but all were greyout or disabled. After searching for the solution on net for 2 days i finally get it working by following the steps below.
Findout gid number by typing
# grep vboxusers /etc/group
you will get output like this
Note down the number between :XXX: in this case it is 501
Now make sure none of the usb devices attached to the PC.
goto root level and run the follwoing commands
[root@~]# umount /proc/bus/usb
[root@~]# mount -n -t usbfs /proc/bus/usb /proc/bus/usb -o devgid=501,devmode=664
put devgid value which you get above.
Now open your virtubalbox and run the OS, you will see all your USB devices enabled.
Hat Tips: Virtualbox Forum