title: Vagrant over Hyper-V slow shared folder SMB
body: <p>I have a vagrant box that is running on top of hyper-v. All seems to work fine except shared folder. It just incredible slow. Its like stuck on something. I run yarn install and it dint finish even after like a 18 hours of work.. ( it was working and adding new files with with incredible slow speed). I know there a lot of small files ( ~80k was created during yarn install until i cancelled it), but no way it should take 18 hours to create such amount of files, and i have a fast ssd. I tried to copy this files over smb inside windows itself and all copied withing few minutes.</p>
  
  <p>I checked process load when its running, everything near zero. No cpu usage, a lot of free mem. </p>
  
  <p>Host system : windows 10</p>
  
  <p>Guest system : ubuntu 16.04</p>
  
  <p>Here is my vagrant file:</p>
  
  <pre><code># -*- mode: ruby -*-
  # vi: set ft=ruby :
  
  
  Vagrant.configure("2") do |config|
  
    config.vm.box = "kmm/ubuntu-xenial64"
    config.vm.provider "hyperv"
    config.vm.network "public_network"
  
    config.vm.synced_folder 'C:/Dev/PycharmProjects/scrapers', '/opt/scrapers', disabled: false, type: "smb", smb_username: "xxx", smb_password: "xxx", mount_options: ['vers=2.1']
    config.vm.synced_folder '.', '/vagrant', disabled: false, type: "smb", smb_username: "xxx", smb_password: "xxx", mount_options: ['vers=2.1']
  
  
    config.vm.provider "hyperv" do |h|
      h.enable_virtualization_extensions = true
      h.differencing_disk = true
      h.ip_address_timeout = 240
      h.memory = 1024
      h.cpus = 4
      h.vm_integration_services = {
        key_value_pair_exchange: true,
      }
    end
  
  
  end
  </code></pre>
  
  <p>I tried mounting with vers=3.0 with the same result. </p>
  
  <p>I even tried to copy that folder on guest machine to another one and it just stuck, it copies like 20 files and then nothing happens after it for few hours.</p>