One of the significant disadvantages of Hyper-V over other hypervisors (for example, VMWare ESXi or Proxmox) is the lack of a feature of redirecting USB devices from the host to virtual machines. Since version Hyper-V 2012 R2, there have been a number of changes regarding USB Passthrough options, but this functionality is still inferior to those of competitors. In this article, we will discuss the specifics of USB redirection in Hyper-V.

USB passthrough refers to the ability to redirect a USB device from the host hypervisor (or over the network from another server/device) to a virtual machine. Using a USB passthrough, you can redirect a USB stick, token, USB dongle, modem, or any other device connected to the physical host’s USB port to the virtual machine.

The bad news is that Hyper-V doesn’t support full-featured USB passthrough. You cannot redirect an arbitrary USB device from a physical host to a virtual machine (VMWare is much better with this – see the article USB passthrough in VMWare ESXi). There are several built-in options for using an external USB device in a Hyper-V VM, but they all have significant limitations. Currently, you can use the following ways to redirect a USB device to Hyper-V virtual machine.

You can fairly easily redirect a host-attached USB drive directly inside any running Hyper-V virtual machine. Let’s see how to give a Hyper-V virtual machine direct access to the host’s USB drive.

That’s all! You have directly connected external USB media into Hyper-V virtual machine and now can use it.

To safely remove the USB drive, you can open the Hyper-V Manager console and go to the virtual machine settings window. In the SCSI Controller section, select the hard drive you want to remove and click Remove. Save your changes. After that, you can physically remove the hard drive from the USB port of the Hyper-V host.

In the version of Hyper-V introduced in Windows Server 2012 R2/8.1, any USB device can be forwarded to a virtual machine from a client computer using Enhanced Session Mode (ESM). The Hyper-V Manager tool vmconnect.exe is used to connect. It allows you to connect to the virtual machine console and select the USB devices you want to redirect.

First you need to enable Enhanced Session Mode in the Hyper-V server settings. This can be done using PowerShell:

Set-VMHost -EnableEnhancedSessionMode $true

Or in the Hyper-V Settings -> Enhanced Session Mode.

Restart the Hyper-V Virtual Machine Management service: Get-Service vmms | Restart-Service

In the Integration Services section of the VM settings, you must enable the Guest Services option.

In order to redirect the USB device through Enhanced Session Mode, you need to open the Hyper-V console, select the virtual machine, and click the Connect button. Or you can run the vmconnect.exe tool (Virtual Machine Connection), specify the Hyper-V server and the virtual machine name. The vmconnect tool supports some command line options, so you can give a customized bat file with the options you want to users.

If the VM supports Enhanced Session Mode, a window similar to the RDP connection properties will appear. Click Show Option -> Local Resources -> Local device and resources -> More.

Select the USB devices on your computer to be redirected to the VM. If the device you want is not currently connected, select the “Other supported Plug and Play (PnP) devices” and “Devices that I plug in later options”.

Now all USB devices connected to your computer will be automatically available in the console session of the Hyper-V virtual machine.

Key features and limitations of Hyper-V Enhanced Session Mode:

This method is similar to redirecting USB devices from local host over an RDP session. We won’t consider this in more detail.

If you are redirecting USB devices over the network (USB over IP or over an RDP session), you can still access the USB key even after migrating the virtual machine to another host (Hyper-V Live Migration / VMware vMotion).