Two Ubuntu VM on Laptop using Virtaul Box

Hi, i am trying to setup Master and Slave configuration for Kubernetes cluster, i have successfully setup both of them individually but when i am trying to run both the VM together [ i believe it should be running ] in virtualbox interface, oracle VM is throwing this error


  1. Downloaded ubunu VDI from
  2. Create VM 1 for Master from that VDI and set that up as my master
  3. Created VM 2 for slave from same VDI and set that up as my slave
  4. Trying to Start both of them but only one run at time

In a nutshell i able to run only one VM at a timeā€¦ either Master or Slave.


Failed to open a session for the virtual machine ubuntu-Master-Updated

Locking of attached media failed. A possible reason is that one of the media is attached to a running VM.

Component: SessionMachine
Interface: IMachine {85632c68-b5bb-4316-a900-5eb28d3413df}