How to run XenServer 6.0 on vSphere 5 - with nested Windows Server 2008 R2 VM

It is possible to install XenServer 6.0 in a virtual machine on vSphere ESXi 5 and then with a few tweaks you can even run a nested Windows Server 2008 R2 VM on the virtual XenServer 6.0.

One important step is to execute the following command from the console:

echo 'vhv.allow = "TRUE"' >> /etc/vmware/config

Otherwise, configure like the guide. Once the custom VM has been created, to be able to choose ESXi 5 as operating system, go to Edit Settings -> Options -> Guest Operating System choose 'Other' and then choose VMware ESXi 5.x. This will ensure that you won't receive the "HVM is required for this operation" error when trying to boot the win2k8R2 vm (it is possible to change this after the install of XenServer as well).

Download the install .iso from citrix.com 

Mount iso and install XenServer

When done, you will get startup screen as below

Download XenCenter from citrix.com and install

Add the the XenServer to XenCenter

Create a new VM, choose win2k8 R2 64-bit, mount ISO, install.

Done.