Windows VirtualBox on Mac OS X not recognizing USB Devices

Windows Virtual Machine in VirtualBox on Mac OS X does not recognize any USB devices (i.e. flash drives etc.) that are listed under “Devices” and they are greyed out and unable to mount (refer to picture below).

This can be easily resolved by just un-mounting the drive from Mac OS X to allow Windows to have access to the device and then simply going to “Devices” in VirtualBox and clicking on the device you need to mount.  Step-by-step illustrated instructions are below.

Step 1 : After inserting USB device (flash drive in this case), it is greyed out and not accessible to mount in VirtualBox.

Windows VirtualBox in Mac OS X

Step 2 : Next to your device click on the eject icon in Mac OS X Finder.

Mac OS X Eject

Step 3 :  Now you can return to your Windows VirtualBox and click on “Devices” on the menu bar and go to USB Devices and your device should be highlighted black now, click on the device and it will now be available to you in Windows.

Windows VirtualBox in Mac OS X

  • fdjugiohrsfd

    it didn’t work

    • Michael Wood

      Alternatively, you can create a RAW disk image to reference your physical drive on the host OS.

      Step 1: Plug in your USB drive

      Step 2: Open Disk Utility and click on your USB drive

      Step 3: Click the Info button at the top and look for the Disk Identifier (e.g., disk2)
      If you just want to mount a Volume that is already formatted, click on the Volume and hit Info. The Disk Identifier will then be something like disk2s2

      Step 4: Open Terminal and use VirtualBox Manager to create the image:
      VBoxManage internalcommands createrawvmdk -filename /Users/YourUsername/Desktop/USB.vmdk -rawdisk /dev/disk2

      The path and name of the RAW image are arbitrary. Put it wherever you want and call it whatever you want.

      If you encounter a Resource error, it is because the disk is in use. Open Finder and Eject the USB drive, then run the command again.

      Step 5: Open VirtualBox Manager (GUI), select your VM, and open Settings > Storage. Click on one of your SATA or IDE controllers and hit the Add Hard Disk button. Choose the RAW disk that you created.

      Now you should be able to boot the VM and use the USB drive as a Hard Disk Drive. When you eject the USB drive to use it somewhere else, the files that you’ve written are on the drive just where they would normally be. The RAW image simply points to the physical drive on the Host OS.

      Note: When directing a RAW image to a disk (-rawdisk /dev/disk2), I noticed that OS X kept trying to remount the volume on the disk, which meant I had to keep ejecting it to use it in VirtualBox. I found that this problem went away when I directed the RAW disk to an existing volume on the USB drive (-rawdisk /dev/disk2s2)

  • CodeMonkey

    I am having a similar issue.
    I am running a Linux Virtual Machine in Virtual Box on Mac OS X, trying to access a USB Device. I once was able to access it in the same manner as described above.
    Now, after ejecting the device from Mac OS X Finder, I am still able to select the device in my “Devices” menu in VirtualBox, but I am unable to access the device.
    Through Terminal I can view and access the directory where the device should be (media), but the device itself is not present in this directory, nor is it present anywhere else.

  • CodeMonkey
  • egostino
  • Ngomez

    that’s good.. Excellent.. Thanks

  • Konrad

    Did not work for me either. Mac OS 10.6.8, Virtualbox 4.2.6 + Oracle extensions pack. Any suggestions?

    Disk is greyed out event after applying article’s advice.


    • Fabiano Bertoli

      Try to change the USB port

  • Pingback: Mac上的Windows VirtualBox不能识别USB,或者能识别,但是是灰色 | Swarm's Blog()

  • fabricio


  • Cesar F Nunes

    Muito obrigado amigo. Sua dica me ajudou muito. Um abraço deste brasileiro e sucesso na vida.

  • Nadjil

    I have problem with Virtualbox I can not use the USB. I have Macbook OS X10.8.3 I use Virtualbox to run Window XP with LabVIEW. I have USB board interface it is Grayed out, I try everything to run it. But no way . . . . even other USB want be recognized by the Virtualbox.

    On the VM Virtualbox Manager, both USB port are active . . . . . but grayed out. I try everything but it is not working. Any one can give me adivce how to solve this problem?

    • Nadjil,

      You have tried flash drives and other USB devices and they also don’t work using the eject method?


    • Robert Estlinbaum

      install the Guest Additions CD image.iso appropriate to your version number launch VB, go to settings, usb, add filter, point to usb, unmount on mac finder, launch VB, it should work.

  • Joko Rivai

    Do you have any tutorial for mounting external USB drive on VirtualBoxed Mountain Lion on Windows Host? I mounted the USB drive, attached it within VirtualBox Image, but not recognized by the Mountain Lion.

    • Joko,

      No I don’t have any tutorials on that, something I have never tried, hopefully you will be able to come up with a solution with a little more “Googleing”.

  • the solution

    It still doesnt work because you have to go to virtual box manager. go to settings select the ports tabs. select Usb and click on the add new usb filter!!!!!

    • TheSunriseDangler

      This worked for me!! Thanks a million!!

  • thebeerman

    I see this is an old thread but I tried a lot of different things but nothing seemed to work. I found this on Virtualbox forum and worked perfect. You have to follow the steps.

    by dsluga » 11. Aug 2008, 16:47

    Here is what I did that seemed to work just fine:

    1) connect the USB drive and get to the settings for your Virtual Machine (remember that you cannot access these settings with the VM it running)

    2) Go to USB and setup a filter for the device: With it connected this is really easy. Just click USB on the left and then the plus sign. Select the device that is not playing nice (for me it was called Atapi-6 bridge). You’ll see that the information below is populated. Leave remote to NO and CLICK OK. I left “Enable 2.0 support” checked also.

    3) boot the VM. After everything is up just unplug and replug the device and VB will grab it before OS X does.

    This worked great for me – I hope it works for you too.

  • renoverdinan

    terima kasih!!! (thank you in indonesian)
    it really works!

  • Mark Lloyd

    Mine keeps on mounting is OS X desktop and not in the Windows environment.