A few months back I had been communicating with some of our Engineers out of your Core Platform Team (vSphere) they usually had shared a noteworthy tidbit which I thought Having been worth mentioning to my readers. When designing an electronic Machine either in vSphere or Fusion/Workstation, customers can override the default and specify the unique Firmware boot option whether which can be BIOS or UEFI.

Like the majority of customers, I would not even bother touching this setting hence there is no just assume the product defaults are sufficient. Interestingly, for Microsoft Windows 10 and Windows Server 2016, you will find important implications to remember on whether BIOS or UEFI is applied. A lot of the important because of the default firmware insert vSphere of OSes are BIOS.

To enable Secure Boot for Windows other sorts of OS that supports Secure Boot, UEFI firmware is a really requirement. Support for Secure Boot was first introduced in vSphere 6.5 here is your web site post that will get into more information. On top of Secure Boot, both Windows 10 and Server 2016 will also support a fabulous security capability from Microsoft called Virtualization-based Security (VBS) which in-turn is employed by other features which include Credential Guard as an illustration. As a way to leverage these capabilities, UEFI firmware may be required.

OK, UEFI sounds great, but what would happen if you got Window VMs which were configured with BIOS firmware? Which can be as basic as just reconfiguring the virtual hardware? Well, earlier Windows 10/Server 2016, the result wasn't and you also was bound to re-install the Windows OS as you couldnrrrt simply update the Firmware while preserving the OS. Decided on way more, this became quite painful since you then were required to schedule extensive downtime to transfer the and thereafter re-build the gps watch. With Windows 10 or newer, Microsoft is now offering a supported path to convert an OS disks using Master Boot Record (MBR) for your GUID Partition Table (GPT) which UEFI requires. The tool known as MBR2GPT.

Extremely effective advanced workflow for converting a Windows VM from BIOS to UEFI firmware:

As with any difference in your environment, take precaution by following a backup on the VM and/or taking snapshot so that you can revert changes
Run the MBR2GPT tool within Windows OS
Shutdown the Windows VM (update vHW if required)
Change the firmware using the Windows VM from BIOS to UEFI
Power on your Windows VM

Around the example below, I shall be demonstrating the conversion process to get a Windows 10 VM that had been deployed using BIOS firmware. Since vSphere currently only supports Secure Boot and not necessarily the VBS feature, the instructions below will subject to VMware Fusion (however, the tactic to enable Secure Boot can be applicable to vSphere). Both Fusion 10 and Workstation 14 have added support for the Secure Boot and VBS, but vSphere customers could even benefit by enabling Secure Boot thus to their Windows 10/2016 VMs.

Step 1 - Lets verify that we are using MBR by applying PowerShell along with Get-Disk command.

Step 2 - Readily validate the disk making use of MBR2GPT tool leading up to conversion. Technically, MBR2GPT tool claims to run in an exceedingly WindowsPE environment, nevertheless you can override that by passing in /allowFullOS flag by running the following command:

MBR2GPT2.EXE /validate /allowFullOS

for Windows 10 & Server 2016
Posted on 10/20/2017 by William Lam

Season back I'm talking with a couple of our Engineers on the Core Platform Team (vSphere) they had shared a stimulating tidbit that i thought I started worth mentioning to my readers. When designing an online Machine either in vSphere or Fusion/Workstation, customers have the option to override the default and specify the actual Firmware boot option whether which is BIOS or UEFI.

Similar to customers, They're legal . even bother touching this setting and i also just assume these units defaults are sufficient. Interestingly, for Microsoft Windows 10 and Windows Server 2016, usually there are some important implications to recognise on whether BIOS or UEFI must be used. A lot of the important considering that the default firmware key in vSphere for such OSes are BIOS.

You need to enable Secure Boot for Windows or another OS that supports Secure Boot, UEFI firmware can be described as requirement. Support for Secure Boot was basically introduced in vSphere 6.5 here is your web page post that gets into additional info. And also Secure Boot, both Windows 10 and Server 2016 will also support a fabulous security capability from Microsoft called Virtualization-based Security (VBS) which in-turn used by more features for example , Credential Guard which include. And therefore leverage these capabilities, UEFI firmware is usually required.

Note: The ESXi Hypervisor will also support Secure Boot for itself, for more details read this short article here.

OK, UEFI sounds great, but visualize you might have Window VMs which had been configured with BIOS firmware? Might it be simply by just reconfiguring the virtual hardware? Well, prior to Windows 10/Server 2016, the perfect solution wasn't any and also was required to re-install the Windows OS because you was unable to simply update the Firmware while preserving the OS. Obviously, it was actually quite painful during the time you then needed to schedule extensive downtime to transfer the particular followed by re-build the gps device. With Windows 10 or newer, Microsoft is now offering a supported answer convert an OS disks using Master Boot Record (MBR) towards a GUID Partition Table (GPT) which UEFI requires. The tool is addressed as MBR2GPT.

Right here is dangerous workflow for converting a Windows VM from BIOS to UEFI firmware:

As with any improvement in your environment, take precaution by doing a backup using the VM and/or taking snapshot as a way to revert changes
Run the MBR2GPT tool while in the Windows OS
Shutdown the Windows VM (update vHW if required)
Change the firmware with the Windows VM from BIOS to UEFI
Power around the Windows VM

In the example below, I am demonstrating the conversion process to get a Windows 10 VM that's deployed using BIOS firmware. Since vSphere currently only supports Secure Boot by no means the VBS feature, the instructions below will based upon VMware Fusion (having said that the method to enable Secure Boot is furthermore applicable to vSphere). Both Fusion 10 and Workstation 14 have added support equally for Secure Boot and VBS, but vSphere customers can even benefit by enabling Secure Boot with regards to their Windows 10/2016 VMs.

Step 1 - Lets verify that we are using MBR by using PowerShell and the Get-Disk command as shown inside screenshot below:

Step 2 - Readily validate the disk making use of MBR2GPT tool before conversion. Technically, MBR2GPT tool is meant to run inside the WindowsPE environment, nonetheless you can override that by passing in /allowFullOS flag by running the accompanying command:

MBR2GPT2.EXE /validate /allowFullOS

Step 3 - If validation was successful with no errors were thrown, we're able now perform conversion by running the below command:

MBR2GPT2.EXE /convert /allowFullOS

The conversion process pretty quick and once they have completed, go on and shutdown the OS.

Step 4 - Reconfigure the VM's firmware from BIOS to UEFI. For vSphere VM, always have vHW13 and with Fusion/Workstation ensure that you have vHW14 you need to enable Secure Boot. As a way for Secure Boot in Fusion, the settings are only according to the Advanced to acquire a VM with regards to vSphere-based VMs, it should be inside of the organization "Boot Option" as shown within screenshot above.

If you are using the latest form of Fusion/Workstation, everyone also has the contrary as a way for the popular VBS feature, simply appear into the box and feature can be consumed within Windows 10 and Server 2016. After you've saved improvements, do not delay - power on the VM.

Step # 5 - When VM as started regress to something easier, you can easliy login and verify the conversion was successful along with the Get-Disk cmdlet. As you expected, our OS disk should now show GPT other than MBR

Perhaps you have realized preparations to get the pretty effortless and OS re-installation isn't any longer required if you have defaulted towards BIOS firmware which is certainly typically the default if you should make a new Windows 10 or Server 2016 VM in vSphere. Individuals told in which the default firmware version will change to UEFI in a future update of vSphere , but for backwards compatibility purposes, we can not simply the complete system vertically current default. This is exactly something to aware about when provisioning new Windows 10/2016 VMs by either including this content with a runbook, leverage a VM Template or via Automation in places you can control the firmware type.