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[SOLVED] Vbox 4.1: Failed to access the USB subsystem.

Posted: 3. Oct 2011, 14:26
by randyjames
1. Setup XP machine generic on Vbox running under Ubuntu Maverick 10.10.
2. Clicked on 'General', got this message:
Failed to access the USB subsystem.

VirtualBox is not currently allowed to access USB devices. You can change this by adding your user to the 'vboxusers' group. Please see the user manual for a more detailed explanation.

Details:
Result Code: NS_ERROR_FAILURE (0x00004005)
Component: Host
Interface: IHost {dab4a2b8-c735-4f08-94fc-9bec84182e2f}
Callee: IMachine {5eaa9319-62fc-4b0a-843c-0cb1940f8a91}
I added the vbox user to the 'vboxusers' group, and it made no difference. I looked for a more detailed explanation in the user manual, and found 'USB not working'. Apropos the suggestions there:

I found no references to 'usbfs' or '/proc/bus/usb' anywhere on the Host. However, I found vbox script entries in /etc/init.d and /etc/udev/rules.d, and some character devices in /dev and /dev/vboxusb that appear to have been setup by vbox. However, nothing which resembles the 'usbfs' referenced in the docs. (BTW, I checked my Ubuntu Lucid 10.04 installation, and it appears to be configured very similarly to the 10.10 version.)

The only way I can proceed is by turning off USB devices entirely. I have not yet gone ahead with my attempt to setup a Windows XP guest, so I don't know if turning off the usb features in the VM will cause a problem getting it to boot. However, it is a problem going forward if I'm unable to access usb from that guest. Questions:

1. Is this problem in any way related to the thread "Failed to access the USB subsystem on Windows 7"?

2. Is there a later build which solves this problem?

3. If not (2), is this a known problem and is there a prospect of getting it fixed in the near future?

Thank you in advance for any assistance.

Re: Vbox 4.1: Failed to access the USB subsystem.

Posted: 3. Oct 2011, 14:48
by Perryg
I added the vbox user to the 'vboxusers' group, and it made no difference.
But did you reboot the host? Permission changes require a minimum of log off and back on.

The error message looks like you have failed to install the Extension Pack that is required with VirtualBox version 4.* How to install Extension Pack

Re: Vbox 4.1: Failed to access the USB subsystem.

Posted: 3. Oct 2011, 14:49
by Martin
Did you relogin or reboot after adding your user to the vboxusers group? Are you using Vbox from the Ubuntu repositories or downloaded from virtualbox.org?

Re: Vbox 4.1: Failed to access the USB subsystem.

Posted: 4. Oct 2011, 16:12
by randyjames
I did not know you had to relogin in order for permissions to take affect. Problem solved. Thanks for the quick response.