In this bog, I will be validating if the “ESXi QuickBoot” feature works in Nested mode i.e. running ESXi in a VM. First of all you must know exactly how QuickBoot works and all the requirements it has. To do this I will use the VMWare portal documentation as a reference:

Quick Boot is a vSphere feature that speeds up the upgrade process of an ESXi server.  A regular reboot involves a full power cycle that requires firmware and device initialization.  Quick Boot optimizes the reboot path to avoid this, saving considerable time from the upgrade process.

Understanding ESXi Quick Boot Compatibility



  • The manufacturer’s platform must be compatible
  • All device drivers must be supported

Limitations in vSphere 7.0:

  • TPM is disabled

Limitations in vSphere 6.7:

  • TPM is disabled
  • There are no VMs with passthrough devices configured.
  • No vmklinux drivers loaded on ESXi.

The VMware documentation includes a list of server manufacturers that support this technology for reference see the link in the VMware documentation knowledge Base .

For ESXi 7.0 or newer versions, you can check the hardware compatibility here:

  • Quick Boot on Dell EMC
  • Quick Boot on HPE
  • Quick Boot on Cisco
  • Quick Boot on Fujitsu
  • Quick Boot on Lenovo

In this lab I will test QuickBoot using Nested Virtualization. It is important to clarify that this is a test/dev scenario. To use this technology in production environments it is needed to activate the QuickBoot option from VMware Update Manager or the renamed Lifecycle Manager. If you are interested I leave a video here.

Updates Installation with vSphere ESXi QuickBoot

[root@comp-01a:~] esxcli hardware platform get
Platform Information
   UUID: 0x27 0xa8 0x30 0x42 0xa3 0xf9 0x54 0xcf 0xe2 0xa3 0x10 0x1d 0xfd 0xb8 0x21 0xd0
   Product Name: VMware7,1
   Vendor Name: VMware, Inc.
   Serial Number: VMware-42 30 a8 27 f9 a3 cf 54-e2 a3 10 1d fd b8 21 d0
   Enclosure Serial Number: None
   BIOS Asset Tag: No Asset Tag
   IPMI Supported: false

The first step to activate QuickBoot is to validate the server compatibility. For this it is mandatory to connect via SSH to the ESXi server to execute the command In this case the command confirmed that my platform is compatible.

[root@comp-01a:~] /usr/lib/vmware/loadesx/bin/
This system is compatible with Quick Boot.

Once the server is validated as compatible, we can activate the QuickBoot function with the command loadESXEnable -e.

[root@comp-01a:~] /bin/loadESXEnable -e
INFO: LoadESX Enabled
INFO: Precheck options:
INFO:   All prechecks are enabled.

The final step to activate the QuickBoot function would be to load the QuickLaunch configuration by using the command

[root@comp-01a:~] /usr/lib/vmware/loadesx/bin/
DEBUG: LoadESX scripts are up to date.
INFO: Enabling QuickLaunch kernel preload
DEBUG: Using a ramdisk at /tmp/loadESX for intermediate storage
INFO: Target version: 7.0.2-0.0.17867351
DEBUG: Install boot module "vmware_e.v00" with size 0x2ec40
DEBUG: Install boot module "vmware_f.v00" with size 0x1e3582f
DEBUG: Install boot module "vsan.v00" with size 0x25f08a8
DEBUG: Install boot module "vsanheal.v00" with size 0x80ebe0
DEBUG: Install boot module "vsanmgmt.v00" with size 0x18957cc
DEBUG: Install boot module "xorg.v00" with size 0x358c40
DEBUG: Install boot module "gc.v00" with size 0xe077
DEBUG: Install boot module "imgdb.tgz" with size 0x192800
DEBUG: Install boot module "state.tgz" with size 0x21a00
INFO: loadESX is ready ...
INFO: Performing QuickLaunch kernel preload...

I am including two videos so you can see the speed of the QuickBoot technology when the server is rebooted.

VMware vSphere Normal Boot:

VMware vSphere QuickBoot: