How to install and clone nested ESXi VM?

By | March 23, 2016

Last week I needed to prepare a small VMware test environment for my customer as I did a my customized VMware ICM training 🙂 I prepared nested ESXi VMs based on two main steps:

  • Creating a VM with ESXi OS and adding two parameters into VM vmx file.
  • Reconfiguring Virtual Switch/Port Group where ESXi VM will be connected.

However when we need to clone a nested ESXi VM (we don't want to install each VM manually, right? 🙂 we have to do some additional steps mentioned later in this post. I recommend to specify a small vmdk disk (max 5GB).

Creating a nested ESXi VM

As I already mentioned in post here, when we need to run a nested hypervisor (ESXi or Microsoft Hyper-V) we need to do some steps:

  1. Create a new VM on vSphere. In this case, we need to create a VM with ESXi.
  2. Power off the VM.
  3. If use Web Client please right click on VM and select Edit Settings. On Virtual Hardware tab, collapse CPU and change CPU/MMU Virtualization option to Hardware CPU and MMU. Then click OK.

    Change CPU virtualization option via Web Client

    Change CPU virtualization option via Web Client

  4. Also we need to add two settings into vmx file by right clicking on VM and removing the VM from inventory.
  5. Locate the VM folder on datastore, download a VM .vmx file to your desktop.
  6. Open the VM vmx file and add two below options at the end of file. Save the file.

    hypervisor.cpuid.v0 = "FALSE"
    vhv.enable= "TRUE"

  7. Add to inventory/Register the VM again.
  8. Install ESXi OS following this guide.

Reconfiguring Virtual Switch/Port Group

We need to enable/accept Promiscuous Mode and Forged Transmits on Virtual Switch where ESXi VMs will be connected. Select ESXi host via vSphere client and go to the Configuration tab --> Networking --> click vSwitch properties --> Security tab.How to install and clone nested ESXi VM 2

Preparing ESXi VM to cloning

Before cloning our ESXi VM, we need to do two steps:

  1. Add an advanced settings to automatically update the VMkernel's MAC Address whenever the Virtual Machines's network adapted MAC Addresses changes (it happens during cloning a VM).

    esxcli system settings advanced set -o /Net/FollowHardwareMac -i 1

  2. Remove the current System UUID from /etc/vmware/esx.conf to be sure that a new UUID will automatically be generated when ESXi VM boots up after cloning.

    vi /etc/vmware/esx.conf

    Find a line with uuid by typing /uuid then clicking Enter:

    How to install and clone nested ESXi VM
    Then type dd to remove the line and wq! to save and close the file.

  3. Power off the ESXi VM.

Now you can clone ESXi VM properly..

Note: If you do not do above steps before cloning, ESXi VMs would not contact (e.g. no ping) each other in the same cluster or vCenter. In my case, I had problems with VMotion.

Update: If you clone ESXi VM with already formatted vmfs datastore, you need to run the following command after booting nested ESXi VMs (on each):

esxcli storage vmfs snapshot resignature -l volume

Author: Mariusz

Architect (~ 15 years experience based on passion...) with strong background as a System Administrator and Engineer. Focused on Data Center Solutions: Virtualization/Cloud Computing and Storage/Backup Systems. Currently living in Poland.