ESXi VMB 411 Halting: Virtualbox Nested VT-X/AMD-V greyed out

In this article, we shall discuss how to fix “ESXi VMB 411 Halting: Virtualbox Nested VT-X/AMD-V greyed out. Nested virtualization empowers users to run virtual machine instances within other VMs, enabling the customization of virtualization environments. Compute Engine enhances nested virtualization by incorporating Intel VT-x instructions into VMs. Please, see Using IBM Library with Veeam, Veeam Backup and Replication Disk I/O with diskspd, and Fixing AIX Veeam agent job startup delay issue.
This integration enables the hypervisor already present on a VM to execute additional VMs upon their creation. “. Please see how to Fix Git is not recognised as an internal or external command, and the differences between vSphere and ESXi and vCenter.
Why was the error “ESXi VMB 411 Halting prompted?
Encountering issues with ESXi and a Virtual Machine (VM) with error “411” halting could be due to numerous reasons. This error was prompted when I was installing ESXi on VirtualBox.

As you can see below resulted because the Nexted VT-X/AMD-V was not enabled.

Furthermore, check if there are resource constraints on the ESXi host, such as CPU, memory, or storage. Specifically for me, this was the sole reason for my issue. Therefore, review the VM configuration settings, including CPU, memory, and disk configurations. Ensure that they are set appropriately for the VM’s workload.
Please see how to enable the Virtual Machine Platform Windows Feature and ensure Virtualization is enabled in the BIOS. Also, see how to enable or disable automatic login on macOS: Fix username greyed out for automatic login, and how to “Fix Keep personal files and apps option greyed out during Upgrade“.
Solution: Enable Nested Virtualization
Nested virtualization is the ability to run a virtual machine inside another virtual machine. In the case of VirtualBox, it generally doesn’t expose the necessary virtualization extensions to virtual machines running inside it. Therefore, we have to enable it.
Note: Oracle VM VirtualBox supports nested virtualization on host systems that run AMD and Intel CPUs. This feature enables the passthrough of hardware virtualization functions to the guest VM.
That means that you can install a hypervisor, such as Oracle VM VirtualBox, Oracle VM Server or KVM, on an Oracle VM VirtualBox guest. You can then create and run VMs within the guest VM.
To fix this issue, you can navigate to the VirtualBox installation folders. You can do this also from the VirtualBox environment itself.

Type”cmd” on the bar that is highlighted below. In the CMD pop-up, type the following command below.
VBoxManage modifyvm --nested-hw-virt on

To see if this has been enabled. Launch VirtualBox, right-click on the VM and click on settings as you wish.

As you can see, the issue has been resolved.

Note: Nested virtualisation introduces security concerns, with one of the main issues being the expansion of the code base of host hypervisors. This expansion, in turn, increases the attack surface due to known security bugs. Additionally, researchers have identified poor I/O performance in nested VMs.
Additional Errors to be aware off when resolving this issue
VBoxManage is not a recognised as in internal or external command: Fix VBoxManage could not find a registered machine named “esxi”

The Registered machine name is case sensitive. Enter the name in cap locks as shown ion the VM and rerun the command.
In order to resolve the error “VBoxmanage is not recognized as an internal or external command, ensure that you are running the command from the right directory as shown below.

The PATH is the list of directories of which Windows can run executables from. If this is not correct, you may have to modify your environment variable to reflect this path. To do this from the command prompt, use the command below.
set PATH=%PATH%;"C:\Program Files\Oracle\VirtualBox"
I hope you found this issue useful on how to fix “ESXi VMB 411 Halting: Virtualbox Nested VT-X/AMD-V greyed out”. Please feel free to leave a comment below.