My global Vagrant configuration (~/.vagrant.d/Vagrantfile)

Vagrantfile

Vagrant.configure("2") do |config|
  # Use the vbguests coming with the box image
  if Vagrant.has_plugin?('vagrant-vbguest')
    config.vbguest.auto_update = false
  end

  # Use linked clones to save disk space and import time
  config.vm.provider "virtualbox" do |v|
    v.linked_clone = true
  end
end