Parallels WorkStation 2.2, 50-99u, EDU, ESD, DE WWL2XL-A04-DE ユーザーズマニュアル

If you receive the "Unable to connect USB device" message while trying to connect 
an USB device to your virtual machine on a computer running Linux primary OS, the most 
probable cause is that you do not have permissions to access USB devices. To fix the problem: 

1  Check if an usb-operating group exists in your Linux primary OS. 

2  If the group exists: 

ƒ  In the Terminal, issue the command 

to gain root privileges. Enter the password to the root account when you are asked 
for it. 

ƒ  Include into this group users who have to have an access to USB devices. 

ƒ  Run the  

command to leave the root account. 

ƒ  Proceed to step 4. 

3  If the group does not exist: 

ƒ  In the Terminal, issue the command 

to gain root privileges.  

ƒ  Create a group and include into it users who have to have an access to USB devices. 

ƒ  In the /etc/fstab file edit the string that mounts the usbfs. Devgid parameter should 

contain the identifier of the group created in the previous step.  

usbfs        /proc/bus/usb usbfs   devgid=<USB 
gid>,devmode=0664 0 0  

This option will of course only work if you have the relevant support compiled in your 
kernel. 

ƒ  Run the  

command to leave the root account. 

4  Restart your Linux primary OS.