Add two or more disks to system using Vagrant

Vagrantfile

VAGRANTFILE_API_VERSION = "2"

Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
  config.vm.box = 'base'

  config.vm.provider "virtualbox" do |vb|
    disk_num = 4
    disk_size = 4096
    i = 0
    while i < disk_num do
      file_to_disk = "./box-disk#{i}.vmdk"
      unless File.exist?(file_to_disk)
        vb.customize ['createhd', '--filename', file_to_disk, '--size', disk_size]
      end
      vb.customize ['storageattach', :id, '--storagectl', 'SATA Controller', '--port', i + 1, '--device', 0, '--type', 'hdd', '--medium', file_to_disk]
      i += 1
    end
  end
end