Can create Server2025 VM in ESXi 8 but not vCenter 8?!

[csinCleveland]

Hi there,

Hopefully someone can help me out.  

We have upgraded our systems to vSphere 8.  The ESXi host is v8.0.2 while vCenter is at v8.03.

For a system upgrade we are about to undertake, we plan to use Windows Server 2025 in the VMs.  After doing some testing, I'm seeing the following: Windows Server 2025 is not listed as an option in the list of OSes (highest version is Server 2022) when creating a new VM.  However, I've discovered if I log into the ESXi host and create a VM, Server 2025 is listed (I haven't actually created a VM using that, I assume it works...).

Server 2025 is listed as an OS choice in an older version of ESXi but not in the newer version of vCenter?!  This to me is backwards.  I'm looking online; the version of vCenter I have should show Server 2025 but it's not.  Plus, if the underlying ESXi host allows/supports something, you would think vCenter running on the same host would let you select that OS as well (plus, vCenter is newer than the host!).

Any idea what the problem is and how to fix it?  I'm not totally upset as there is a workaround; I can use Server 2022 as the OS when I create a VM and Server 2025 will install into that VM and function fine (I have done that already...).  My thing is this makes me think there is a problem of some sort.  If there is a problem, could another issue be waiting to rear it's **** head, one I may not be able to ignore?

Thanks,

Chris Smith
[e-mail]

[Adam Ru]

Hi Chris,

Thanks for sharing the details — I understand the confusion.

To clarify, *Windows Server 2025 is officially supported starting with
vSphere 7.0 Update 3 and all later releases*, including your current setup
with ESXi 8.0.2 and vCenter 8.0.3.

When creating a VM in the *vCenter UI*, please make sure to:

-

Select *"Compatibility: ESXi 8.0 and later"*, which corresponds to *hardware
version 20*.
-

Windows Server 2025 should be listed as an option when the correct
hardware version is selected.

However, if you select *hardware version 19* (which targets ESXi 7.0 and
later), Windows Server 2025 may not appear in the guest OS list. In that
case, choosing *Windows Server 2022* is still a valid and supported
workaround — the VM will install and run Windows Server 2025 just fine.

refer to
https://knowledge.broadcom.com/external/article/371344/windows-server-2025-guest-os-option-is-n.html

Adam

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[csinCleveland]

Hi Adam Ru,

First off, thanks for the response.  That's a huge deal.

The response above makes perfect sense and I [believe] I fully understand it all.  

When I create a new VM, for 'Select Compatibility' I can select between:

• 'ESXi 8.0 and later' which states in part "Virtual Machines using hardware version 20 are compatible...".
• 'ESXi 8.0 U2 and later' which states in part "Virtual Machines using hardware version 21 provide the best performance...".
• Other compatibility levels with hardware versions less than level 19.

So if I select either level from the first two bullets above, I should see 'Windows Server 2025' listed as an option in the OS list on the next page assuming I select Windows as the family of operating systems.  Yet, I'm not.  I will point out on the same server which uses ESXi v8.x if I do this then I do see 'Windows Server 2025' listed in the OS list.

The weird things is, I have a VSAN where we upgraded to vSphere v8 as well (different hardware from above which is not a vSAN).  In it's vCenter, if I try to create a VM I can see 'Windows Server 2025' in its OS list.

I am aware I can choose Server 2022 and install Server 2025 just fine.  In fact, I tesed that on the system in question before I left yesterday and it did indeed work fine.

My concern is I'm seeing this issue when by all accounts I shouldn't be.  Server 2025 should show up in the OS list according to everything I'm looking at and yet its not.  Any idea why?  Is this a sign of a larger problem and I may experience a severe issue in the future?

You know, I'm beginning to wonder if I need to reinstall vCenter on this ESXi host.  Maybe that will trigger something...

Thanks again for any thoughts you may have.

Respectfully,

Chris Smith

[Adam Ru]

Hi Chris

You're absolutely right — there are indeed some inconsistencies between the
ESXi UI and the vCenter UI. These differences stem from historical reasons.

For example, we initially pre-enabled the "Windows Server 2025" guest OS
option in ESXi 8.0 before its official release. However, once Microsoft
became aware of this, they requested us to temporarily hide that option
until closer to the official launch.

That said, this is purely a display/UI issue and does not impact VM
functionality in any way. As long as you're running a supported version of
ESXi with Windows Server 2025, you're good to go. We thoroughly tested
Windows Server 2025 before officially announcing support for it.

Best regards,
Adam

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with it, or attached to it, are confidential and are intended solely for
the use of the individual or entity to whom it is addressed and may contain
information that is confidential, legally privileged, protected by privacy
laws, or otherwise restricted from disclosure to anyone else. If you are
not the intended recipient or the person responsible for delivering the
e-mail to the intended recipient, you are hereby notified that any use,
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this e-mail is strictly prohibited. If you received this e-mail in error,
please return the e-mail to the sender, delete it from your computer, and
destroy any printed copy of it.

[csinCleveland]

Thanks for the responses Adam.  That's good stuff.  I'll keep all of this in mind.  We can consider this matter closed.

Thanks again.

Respectfully,

Chris Smith

[ChrisLeblanc]

In working on this with a member of our windows team, I did discover that VMWare tools will still report it as 2025 even if you can't set it as an option. As said, it doesn't affect it from working. Not sure about nowadays but in the past the type of OS only determined which VMWare tools ISO was mounted behind the scenes.. ie windows.iso or linux.iso