After installing VMware ESX 4.1 with a connected USB (for USB passtrough in one of my VM’s) disk in my VMware Workstation 7.1 I received this error:

0:00:00:56.791 cpu0:4096)Warning: /vmfs/devices/char/vmkdriver/usbpassthrough not found

Solution:

- Edith the Virtual Machine hardware

- Add new hardware: USB Controller

- ^ Select: Show all USB input devices;

- ^ The USB Storage device is detected;

- ^ Connect the hardware en present it to the virtual machine

- Reboot the ESX 4.1 host

The error disappears and I can use my USB storage disk now for USB pass trough