A few weeks back, I offered free Windows assistance as long as the #StayAtHome lock-down continues. One of the emails I have received was from a user who asked if there’s anything one could do to speed up file transfer between a Hyper-V host and a virtual machine using Enhanced Session Mode.
I thought that instead of simply emailing the user the explanation and how to resolve it, I’d write about it here on Win10.guru, and send him the link. This way our other readers, too, might get slow file transfer between host and guest resolved. Because Enhanced Mode is based on Remote Desktop Protocol, this also applies to those using Remote Desktop Connection and wondering why file transfer between a remote client and a remote host can sometimes be slow.
The culprit is the notoriously slow Windows Terminal Services connection, the base for RDP. Connecting to a VM in Enhanced Mode, or to a remote host, you will see that the Terminal Services Client (tsclient) is shown as a network device:
All file operations between a Hyper-V host and a guest VM, or a remote client and a remote host, are handled by the terminal services client, not done directly over the network. In this next screenshot, which shows copying an ISO image from a Hyper-V host and pasting it in a guest VM, you will see that file transfer is slow, with minimal network traffic:
Thanks to the slow transfer speed, copying a 4GB ISO image takes close to 10 minutes. Ouch!
Instead of using Copy & Paste over tsclient, use shared network drives. Share a drive or folder on the Hyper-V host / remote client, and map it as a network drive on the guest VM / remote host. In the next screenshot, I have mapped a Hyper-V host shared folder on a guest VM, opened it in the guest’s File Explorer, and copied the same ISO image. I then pasted it onto the guest desktop, with noticeably different results and performance:
You can clearly see that the transfer speed is now over 10 times faster, with the file coming over a gigabit network at almost full speed.
Notice that these same transfer speeds apply regardless of direction, from host / remote client to guest / remote host, or vice versa. Using a mapped network share for all file operations is not only easy, but it really makes a big difference in transfer speed.
If you need some help in drive and folder sharing and mapping a network drive, see these excellent tutorials by Shawn Brink on Ten Forums:
– How to Share Files and Folders Over a Network in Windows 10
– How to Map Network Drive or Disconnect Network Drive in Windows 10
Author: Kari Finn
A former Windows Insider MVP, Kari started in computing in the mid 80’s writing code for VAX / VMS systems. Since then, he’s worked in a variety of IT positions. He specializes in Windows image capture, customization, repair and deployment as well as Hyper-V virtualization. Kari is a proud Team Member at number #1 Windows site TenForums.com.