Enabling nested virtualization

A nested hypervisor enables a virtual machine running on another virtual machine within your Skytap environment and can be run only on specific guest operating systems.


  • This capability is provided as-is without support guarantees.
  • Nested virtualization isn't available for Power A CPU architecture that supports IBM i, AIX, and Linux (on Power) in Skytap. VMs.

Enabling nested virtualization

By default, nested hypervisors are enabled on VMkernel guest operating systems. To use nested hypervisors on other VMs, you must enable nested virtualization support on a per VM basis. To do this:

  1. Navigate to the VM Settings - Hardware page for the VM you would like to edit.
  2. Click Edit in the Guest OS settings section.
  3. Click the checkbox for Enable nested virtualization.
  4. Once this checkbox is selected:

    • Skytap uses the guest OS setting to determine which hypervisors are supported for the virtual machine.
    • Microsoft Windows VMs are enabled for HyperV.
    • Linux and Unix VMs are enabled for KVM and Xen.
    • VMware VMs are enabled for ESXi.

      If your VM uses an ESXi hypervisor, consider installing VMware Tools for Nested ESXi: https://kb.vmware.com/s/article/2009916. This tool helps manage nested virtual machines.

    • Skytap adds “- nested virtualization enabled” to the guest OS name.
    • Skytap doesn’t automatically enable promiscuous mode. To enable promiscuous mode, see Enabling promiscuous mode on a network adapter.

Operating systems that allow nested hypervisors

Following is a list of guest operating system types in Skytap that are allowed to run nested hypervisors. This list doesn’t guarantee that a VM can use nested hypervisors without any issues.

  Guest OS
VMkernel VMware ESX 4.x
VMware ESXi 5.x
VMware ESXi 6.0
VMware ESXi 6.5
Linux CentOS 4/5/6 (32-bit)
CentOS 4/5/6/7 (64-bit)
Debian GNU/Linux 4 (32-bit and 64-bit)
Debian GNU/Linux 5 (32-bit and 64-bit)
Debian GNU/Linux 6 (32-bit and 64-bit)
Debian GNU/Linux 7 (32-bit and 64-bit)
Red Hat Enterprise Linux 5 (32-bit and 64-bit)
Red Hat Enterprise Linux 6 (32-bit and 64-bit)
Red Hat Enterprise Linux 7 (64-bit)
SUSE Linux Enterprise 11 (32-bit and 64-bit)
SUSE Linux Enterprise 12 (64-bit)
Ubuntu Linux (32-bit and 64-bit)
Microsoft Microsoft Windows 7 (64-bit) – “XP Mode”/Virtual PC/VirtualBox
Microsoft Windows 8 (64-bit) – HyperV
Microsoft Windows Server 2008 (64-bit) – HyperV
Microsoft Windows Server 2008 R2 (64-bit) – HyperV
Microsoft Windows Server 2012 (64-bit) – HyperV
Microsoft Windows Server 2012 R2 (64-bit) – HyperV
Microsoft Windows Server 2016 (64-bit) – HyperV

Limitations with nested virtualization

Some Skytap capabilities aren’t available or won’t work correctly for VMs running inside a nested hypervisor.