# File lib/fog/compute/ecloud/models/server.rb, line 162
        def add_disk(size)
          index = disks.map { |d| d[:Index].to_i }.sort[-1] + 1
          vm_disks = disks << { :Index => index.to_s, :Size => { :Unit => "GB", :Value => size.to_s }, :Name => "Hard Disk #{index + 1}" }
          data = service.virtual_machine_edit_hardware_configuration(href + "/hardwareConfiguration", _configuration_data(:disks => vm_disks)).body
          service.tasks.new(data)
        end