vagrant multiple disk bogus

vagrantfile

# -*- mode: ruby -*-
# vi: set ft=ruby :

# All Vagrant configuration is done below. The "2" in Vagrant.configure
# configures the configuration version (we support older styles for
# backwards compatibility). Please don't change it unless you know what
# you're doing.
Vagrant.configure(2) do |config|
  config.landrush.enabled = true
  config.landrush.tld = 'docker.vm'

    # Application Worker Node
    config.vm.define "workernode01" do |workernode01|
      workernode01.vm.box = "ubuntu/xenial64"
      workernode01.vm.network :private_network, ip: "192.168.3.12"
      workernode01.vm.hostname = "worker01.docker.vm"
      config.vm.provider :virtualbox do |vb|
         vb.name = "workernode01"
         line = `VBoxManage list systemproperties | grep "Default machine folder"`
         vb_machine_folder = line.split(':')[1].strip()
         second_diskn1 = File.join(vb_machine_folder, vb.name, 'node-ds.vmdk')
         vb.customize ["modifyvm", :id, "--memory", "2048"]
         vb.customize ["modifyvm", :id, "--cpus", "2"]
         vb.customize ["modifyvm", :id, "--natdnsproxy1", "on"]
         vb.customize ["modifyvm", :id, "--natdnshostresolver1", "on"]
         vb.customize ['createhd', '--filename', second_diskn1, '--size', 10 * 1024]
         vb.customize ['storageattach', :id, '--storagectl', 'SCSI', '--port', 3, '--device', 0, '--type', 'hdd', '--medium', second_diskn1 ]
      end
    end


    # Application Worker Node
    config.vm.define "workernode02" do |workernode02|
      workernode02.vm.box = "ubuntu/xenial64"
      workernode02.vm.network :private_network, ip: "192.168.3.13"
      workernode02.vm.hostname = "worker02.docker.vm"
      config.vm.provider :virtualbox do |vb2|
         vb2.name = "workernode02"
         line = `VBoxManage list systemproperties | grep "Default machine folder"`
         vb2_machine_folder = line.split(':')[1].strip()
         second_diskn2 = File.join(vb2_machine_folder, vb2.name, 'node-ds.vmdk')
         vb2.customize ["modifyvm", :id, "--memory", "2048"]
         vb2.customize ["modifyvm", :id, "--cpus", "2"]
         vb2.customize ["modifyvm", :id, "--natdnsproxy1", "on"]
         vb2.customize ["modifyvm", :id, "--natdnshostresolver1", "on"]
         vb2.customize ['createhd', '--filename', second_diskn2, '--size', 10 * 1024]
         vb2.customize ['storageattach', :id, '--storagectl', 'SCSI', '--port', 3, '--device', 0, '--type', 'hdd', '--medium', second_diskn2 ]
      end
    end

    # Application Worker Node
    config.vm.define "workernode03" do |workernode03|
      workernode03.vm.box = "ubuntu/xenial64"
      workernode03.vm.network :private_network, ip: "192.168.3.14"
      workernode03.vm.hostname = "worker03.docker.vm"
      config.vm.provider :virtualbox do |vb3|
         vb3.name = "workernode03"
         line = `VBoxManage list systemproperties | grep "Default machine folder"`
         vb_machine_folder = line.split(':')[1].strip()
         second_diskn3 = File.join(vb_machine_folder, vb3.name, 'node-ds.vmdk')
         vb3.customize ["modifyvm", :id, "--memory", "2048"]
         vb3.customize ["modifyvm", :id, "--cpus", "2"]
         vb3.customize ["modifyvm", :id, "--natdnsproxy1", "on"]
         vb3.customize ["modifyvm", :id, "--natdnshostresolver1", "on"]
         vb3.customize ['createhd', '--filename', second_diskn3, '--size', 10 * 1024]
         vb3.customize ['storageattach', :id, '--storagectl', 'SCSI', '--port', 3, '--device', 0, '--type', 'hdd', '--medium', second_diskn3 ]
      end
    end

    # Application Worker Node
    config.vm.define "workernode04" do |workernode04|
      workernode04.vm.box = "ubuntu/xenial64"
      workernode04.vm.network :private_network, ip: "192.168.3.15"
      workernode04.vm.hostname = "worker04.docker.vm"
      config.vm.provider :virtualbox do |vb4|
         vb4.name = "workernode04"
         line = `VBoxManage list systemproperties | grep "Default machine folder"`
         vb_machine_folder = line.split(':')[1].strip()
         second_diskn4 = File.join(vb_machine_folder, vb4.name, 'node-ds.vmdk')
         vb4.customize ["modifyvm", :id, "--memory", "2048"]
         vb4.customize ["modifyvm", :id, "--cpus", "2"]
         vb4.customize ["modifyvm", :id, "--natdnsproxy1", "on"]
         vb4.customize ["modifyvm", :id, "--natdnshostresolver1", "on"]
         vb4.customize ['createhd', '--filename', second_diskn4, '--size', 10 * 1024]
         vb4.customize ['storageattach', :id, '--storagectl', 'SCSI', '--port', 3, '--device', 0, '--type', 'hdd', '--medium', second_diskn4 ]
      end
    end
  end

perfectly working , many thanks @dduportal