- Intel VT-x or AMD-V is required for running "Nested Virtualization" which supports nested 32-bit VMs
- Intel EPT or AMD RVI is required for running nested 64-bit VMs.
https://[your-esxi-host-ip-address]/mob/?moid=ha-host&doPath=capabilityYou will need to login with your root credentials and then look for the "nestedHVSupported" property and if it states false, it means you maybe able to install nested ESXi or other hypervisor, but you will not be able to run nested 64-bit VMs, only 32-bit VMs, assuming you have either Intel-VT or AMD-V support on your CPUs.
For more details, take a look at this article for troubleshooting: Having Difficulties Enabling Nested ESXi in vSphere 5.1?
There are some changes with Nested Virtualization in vSphere 5.1 also officially known as VHV (Virtual Hardware-Assisted Virtualization). If you are using vSphere 5.0 to run Nested ESXi or other nested Hypervisors, then please take a look at the instructions in this article. With vSphere 5.1, there have been a few minor changes to enable VHV.
- The new Virtual Hardware 9 compatibility will be required when creating your nested ESXi VM, Virtual Hardware 8 will not work if you are running ESXi 5.1 on your physical host. You will still need to enable promiscuous mode on the portgroup that will be used for your nested ESXi VM for network connectivity.
- vhv.allow = "true" is no longer valid for ESXi 5.1 to enable VHV. A new parameter has been introduced called vhv.enable = "true" that is now defined on a per VM basis to provide finer granularity of VHV support. This also allows for better portability between VMware's hosted products such as VMware Fusion and Workstation as they also support the vhv.enable parameter.
- You can now enable VHV on a per VM basis and using the new vSphere Web Client which basically adds the vhv.enable = "true" parameter to the VM's .VMX configuration file.
Enabling VHV (Virtual Hardware-Assisted Virtualization)
Step 1 - Create a new Virtual Hardware 9 Virtual Machine using the new vSphere Web Client that's available with vCenter Server 5.1.
Step 4 - It is still recommended that you change the guestOS Version to VMware ESXi 5.x after you have created the VM shell, as there are some special settings that are applied automatically. Unfortunately with the new vSphere Web Client, you will not be able to modify the guestOS after creation, so you will need to use the C# Client OR manually go into the .VMX and update guestOS = "vmkernel5"
If you have followed my previous article about How to Enable Support for Nested 64bit & Hyper-V VMs in vSphere 5 you may recall a diagram about the levels of "Inception" that can be performed with nested ESXi. That is, the number of times you could nest ESXi and still have it be in a "functional" state. With vSphere 5.0, the limit that I was able to push was 2 levels of nested ESXi. With latest release of vSphere 5.1, I have been able to push that limit now to an extraordinary 3 levels of inception!
For proper networking connectivity, also ensure that either your standard vSwitch or Distributed Virtual Switch has both promiscuous mode and forged transmit enabled either globally on the portgroup or distributed portgroup your nested ESXi hosts are connected to.
Nesting "Other" Hypervisors
For those of you who feel inclined to run other hypervisors such as Hyper-V, you can do so with latest release of ESXi 5.1. The process if very straight forward just like running nested ESXi host.
Step 1 - Create a Virtual Hardware 9 VM and select the appropriate guestOS. In this example, I selected Windows Server 2012 (64-bit) as the guestOS version.
Step 2 - Enable VHV under the CPU section if you wish to create and run nested 64-bit VMs under Hyper-V
Step 3 - You will need to add one additional .vmx parameter which tells the underlying guestOS (Hyper-V) that it is not running as a virtual guest which in fact it really is. The parameter is hypervisor.cpuid.v0 = FALSE