Forum Discussion
ISSUE - FIXED - Hyper-V VM In-Place Upgrade (IPU) WS 2022 to WS 2025 b26063 fails
- Update on this investigation:
The Windows Boot team looked over logs from my repro and noticed that the upgrade sequence depends on creating a large (500MB) RAM disk and that ramdisk creation is failing due to not enough memory. Since the documented recommendation for Windows Server with Desktop Experience is 2GB, I turned off Dynamic Memory and set the RAM to 2048 GB.
This resolved the issue for me - in-place upgrade now succeeds.
Karl, can you please see if that same mitigation works for you?
If so, I can follow up with the MSLab owners to see if they can change the memory configuration.
Thanks,
Michael
new VM 23048.2159
MSBernstein last update for this tonight, same behaviour
So opposite to you, (unfortunately) I can replicate the problem.
Hope you'll have success to repro it, too. Here it appears to be absolutely reproducible.
One to note, after setup completed to 100% in the online phase, now with 26080 recognize a small difference vs 26063.
The first boot after IPU takes several minutes showing (old) circling balls, where as I would be expecting to see a brief "preparing drivers" + Apply phase with "You are x% there yet - do not shut down..." But this is not showing up just very long boot phase with 26080 now.
With 26063 the reboot was quick (about 2 seconds) and it directly booted into the "wrong" bcdedit as it appears.
With 26080 it seems it is picking the setup bcdentry
in both cases each IPU attempt would generate a new bcdentry. So maybe there is the culprit.
It does not initiate a real visible rollback and the setup bcd remains.
Hyper-V Host settings all default, except on host HCVI / VBS is enabled via Defender Security Center (Core Isolation). And off the bare defaults also vTPM is activated on the Gen2 Secure Boot guest VM.
MicrosoftThe Windows Boot team looked over logs from my repro and noticed that the upgrade sequence depends on creating a large (500MB) RAM disk and that ramdisk creation is failing due to not enough memory. Since the documented recommendation for Windows Server with Desktop Experience is 2GB, I turned off Dynamic Memory and set the RAM to 2048 GB.
This resolved the issue for me - in-place upgrade now succeeds.
Karl, can you please see if that same mitigation works for you?
If so, I can follow up with the MSLab owners to see if they can change the memory configuration.
Thanks,
Michael
Hi MSBernstein this did the trick.
But only for GUI. Core again fails way before as outlined in a previous reply.
for GUI we seem to have a new issue when dynamic memory is enabled.
The extra mile would be if this is 2025 specific or even happened before. It is very common to have dynamic memory enabled. And it is set to 512 min / 512 startup mem here.
It would be great if setup could check this when checking the requirements or we have a more transparence error message when it fails.
edit: another test with dynamic memory on, showed that dynamic memory itself is not the issue.
Using dynamic memory with 1 GB startup memory, 512 GB min memory works fine with the upgrade, so it is certainly the startup memory that should be 1 GB or more.