No USB devices available in VirtualBox

Oracle VirtualBox is unable to list/filter the USB devices attached to my system. As a result, the guest OS is not able to see any USB device either.

This is my configuration:

• Host: VirtualBox 5.0.0 r101573 on Ubuntu 14.04, with Oracle VM VirtualBox Extension Pack installed
• Guest: Windows 7, with VirtualBox Guest Additions installed

I've been trying with a USB flash drive and a Garmin sports watch: when connected to the host, they are both recognised by the system, i.e. they are in the list outputted by the lsusb command.

However, when running VirtualBox, no USB device is actually detected (Enable USB Controller is obviously checked). If I select the VM, then Settings -> USB and I try to add a filter, a tooltip is displayed:

<no devices available>

I've tried different options as USB controller, even tried to attach the devices to different USB ports (2.0 instead of 3.0), but that didn't change anything. Since no USB devices are listed there I assume the problem is with the host, not with the guest.

The USB mouse I have is working in both the host and the guest, but that's probably a device that is treated differently.

The VBox.log does not report anything suspicious regarding the USB, and VirtualBox does not throw any error either.

The same problem occurred when I had VirtualBox 4.3.30 installed.

Is there a way to resolve the issue?

Please add your user name to the vboxusers group with this command:

sudo adduser $USER vboxusers

After that you must logout and login. (For Ubuntu 20.04, a reboot is required)

Please check this for more details:

https://help.ubuntu.com/community/VirtualBox/USB

If you don't have the adduser command, you can do this instead:

sudo usermod -aG vboxusers $USER

Logout and login again in order to reload user's group info and usb device will now show up in the list.

First of all, @csorig's answer is right. You need to be in the vboxusers group. That's the basic.

But if it still doesn't work for any reason... it's not documented anywhere, but I found that USB host device sharing does not work if the system has run out of inotify resources.

You can try running tail -f /var/log/syslog or something like that. If it shows up a message like:

tail: inotify cannot be used, reverting to polling: Too many open files

then you need to increase your inotify watch limit or disable software that is consuming them. In my case it was a continuous backup software running in background.

The basic method to increase this limit is:

echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p