Running nested VM on vSphere 5

What better way to test an entire VMware deployment (vSphere, VDI, vCloud) than to virtualize the whole environment?

Running a VM within a ESXi VM ala Inception style was possible since VI 3.5 days, but required some configuration work, especially if you want to run nested 64-bit VMs. With vSphere 5 however, it is very simple now.

Requirements
1. vSphere 5 – This is tested on ESXi 5
2. CPU that supports Intel VT-x or AMD-V – For better performance, it is recommended that your CPU supports hardware-assisted MMU virtualization (EPT or RVI)

Steps
1. Enable hardware-assisted virtualization (HV) on ESXi host. HV is required to run nested 64-bit VMs. On ESXi 5, HV is disabled by default. Add the following line to /etc/vmware/config file on the physical host. You can do it via Tech Support Mode, direct console or SSH.

vhv.allow = “TRUE”

2. The last step you need to do is to change the Guest OS type for your ESXi VM to “VMware ESXi 5.x”. Note that this option is not available in the create new VM wizard. You need to create the VM first or modify your installed ESXi VM.

After which, your nested 64-bit VM will be able to power on.