esxi 6.7 - how to boot guest in uefi?

[JesterJeff69]

Ok so I have a freshly created vm in esxi 6.7 that I went into the boot options and changed to efi.

Now I have attempted to boot off of the windows 10 1803 iso created from the Microsoft media creation tool and figured... maybe it isn't able to be setup as uefi.

Our imaging process we have on our physical boxes, we boot off of a thumb drive and launch booting a uefi_boot.iso through a custom menu and it does allow us to build a windows 10 box with uefi so I know this works.

Typically we copy the iso to our datastore and can mount and boot but I cant get the uefi vm to boot off of it.

trying to see what I am not doing correctly..

thanks as any help is greatly appreciated.

[continuum]

If you take a texteditor and read the vmx-file of your VM you may find 2 different scenarios:
1. there exists a line:
firmware = "efi"
2, there is no line like that or it says
firmware = "bios"
In the first case your VM uses the EFI-firmware.
In the second case you have a VM with good old BIOS

[JesterJeff69]

Thx.. I checked and I have firmware = "efi"

now I do get booted up into efi for boot manager. I cant boot off of a win10 iso from Microsoft media creation tool, nor can I boot off of our custom uefi_boot.iso that we have used to create physical machines with uefi bios settings...

[JesterJeff69]

and seen here..

[continuum]

Are you sure that the MS tool is configured to create the EFI-bootfiles ?

[JesterJeff69]

No, not sure on the MS tools BUT I know our other custom boot one is... it is how we winpe boot to build win10 boxes that are uefi only...

well done for the day so ill play around with it more tomorrow...

but yes I agree, it seems the vm doesn't agree that the boot media is uefi...

[JesterJeff69]

not sure why I didn't think of this earlier.. I do have an esxi 6.0.. and set it to uefi and it has booted my boot media.. so yes the media is UEFI... just cant get 6.7 to boot it. Well I can still get done what I need too...but still curious how to get it working as I almost upgraded this test server as well. glad I didn't...

[davidmatthewson]

I know this is a little old but I too get exactly the same. I am using MS downloaded install media (ISO) for W2016 and if I keep the Guest partition as MBR and so udner 2Tb, it boots from the ISO in the datastore and installs fine. If I create a 4Tb disk the VM fails to boot from the iso and I get the same error screen as the OP.

I also agree this used to work under 5.x ESXi..

I've set the 'BIOS' to EFI. If I leave it at BIOS them the iso boots but Windows shows 2 x 2Tb disks as it starts to install which is n/g for what we need. I also assume they are MBRs.

Anyone got  a fix pls?

TiA

David

[continuum]

You need GPT for disks larger than 2 TB

[davidmatthewson]

Thanks - yes, I know I need GPT, that's the problem. If I set the VM to use BIOS and keep under 2TB, it boots the MS iso installer OK. No probs.

If I set up a new VM with a 4TB single disk, and set the VM bios to EFI, it fails to boot the MS installation media.

This used to work on 5.x hosts but seems broken on 6.7..

TiA

[davidmatthewson]

OK, I think I can confirm that this is a bug in 6.7.

It is impossible to create a boot volume greater than 2TB, (Yes, EFI boot is enabled in the VM setup instead of BIOS)

My workaround was to use a 3rd part app to convert an MBR 2TB Server 2016 VM to GPT and then increase the disk size.

I can also confirm that this did work in previous versions, (such as 6.0) so something's changed ;}

[It's also worth noting that it might be best practise to make a 500GB boot volume and then attach a D$ of 4TB but in this case we needed a single large volume for special reasons.]

[GuiFei]

I get the same problem with JesterJeff69. But I have already settled the issue.

The key is the ISO file. I started by using a 'Windows Server 2008 R2.iso' that I downloaded almost 8 years ago. Then I download a recent version 'windows_server_2008_r2_sp1_x64_dvd.iso' and I can boot guest in uefi. The problem is solved.