By default, USB devices you plug in to your physical host are not available to your vserver guests. To make all your USB devices available to a specific guest, follow these instructions:
Mount the USB filesystem in the guest
Now we edit the `fstab` file for the guest. The following works on a host running Debian Etch and a guest running Ubuntu 6.06.1. To find the way that `usbfs` is mounted in the host, I used:
cat /proc/mounts | grep usbfs
usbfs /proc/bus/usb usbfs rw,nosuid,nodev,noexec 0 0
Paste this line (or the one that suits your distro) to the end of `/etc/vservers/<guest>/fstab`, and restart the guest.
Now enter the guest, and see if you can see `/proc/bus/usb/devices`. Better still, plug in a USB device and see if it shows up in there.
Information came from this thread (credit: Daniel Hokka Zakrisson) and from followup in IRC on 21 April 2007, again credit to Daniel.