Hyper-V enhanced mode and TSClient

Today, I was processing data in a Hyper-V VM with results being written to a physical host drive (using enhanced mode).

I found it was very slow - around a quarter of speed I normally can write to drive.

Did a bit of digging around and found reason (actually remembered is more accurate) was due to the TSCLIENT interface which interfaces the Hyper-V vms to host drives.

I then tried writing to host drive using a network share instead (had to set up permissions for host drive to be shared), and use an external switch.

This was much faster - around 80% of my normal write speed - I expect a little reduction as using a VM.

I then tried an experiment with no idea if it would work. I created a virtual hard drive on the host drive and attached it in Hyper-V settings as a second hard drive. I could see the drive as a normal local drive in the guest. So when I ran the test again (rebooting to clear any cache), it was slightly faster than the network method.

Obviously the TSCLIENT interface is very inefficient!

As an aside, if using W10 Home as a guest VM, you cannot use TSCLIENT anyway, but you can use the network or vhd method - this is easier (in my opinion) than faffing around with making physical disks offline and works even if you only have one drive (you cannot take host OS drive offline, even if partitioned).