Page 1 of 2

[SOLVED] Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 19. Oct 2021, 10:09
by vbicf
Hi,

I have some old Windows 10 VM (VT-X) that was created when Hyper-V was not enabled in the host. After I enable Hyper-V, that old VM will not start and it will get a bluescreen. Is there a way to fix that old VM machine so that it will start with Hyper-V enabled in the host. I changed the settings in VirtualBox to use Hyper-V Paravirtualization but the blue screen happens again. See here:

If I create a VM from scratch with Hyper-V enabled in the host, the VM will boot fine.

This means something in the old VM is causing the crash. I don't want to reinstall it from scratch.


The version of VirtualBox: 6.1.22

Host: Windows 10 21H1, Guest: Windows 10 20H2

When the VM was created: VT-x/AMD-V enabled, HyperV disabled

installed Guest Additions and Host Extensions

Re: Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 19. Oct 2021, 11:25
by mpack
There is no setting which tells VirtualBox to use Hyper-v, it will do that automatically if Hyper-v is enabled.

You provide scant information about the bluescreen, so that's just about all that can be said for now.

The "Hyper-v Paravirtualization" VM setting has nothing to do with whether the host has Hyper-v. It's a question of what APIs the guest OS supports in order to communicate with VirtualBox. Nothing relevant to your discussion.

Re: Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 19. Oct 2021, 12:35
by vbicf
I have to wait 1 day before posting links to this forum. :?:

Re: Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 19. Oct 2021, 12:48
by mpack
Why would you want to post links? You can upload attachments immediately (*). Images need to be downscaled and trimmed to be below the 128KB size limit.

(*) See the "Upload attachment" tab below the text input box when composing posts.

Re: Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 19. Oct 2021, 13:17
by vbicf
The blue screen when I start the old VM with Hyper-V enabled.

(didn't know you can upload images)

Re: Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 19. Oct 2021, 13:23
by vbicf
VM settings

Re: Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 19. Oct 2021, 13:41
by Martin
You want to run a SQL Server in a Windows 10 VM with only 1 CPU and 2 GB RAM?

Re: Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 19. Oct 2021, 13:46
by vbicf
It is working fine for what I need (small DB). But I also need Hyper-v activated for other stuff.

Re: Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 19. Oct 2021, 14:23
by mpack
One VM log is worth 1000 pictures, and many of the things reported by the log - for example what CPU and how much RAM your host has - will not be found in a VirtualBox settings dialog.

Make sure the VM is fully shut down, then right click it in the manager UI. Select "Show Log" and save "VBox.log" (no other file) to a zip file. Attach the zip here.

Btw, that looks like a guest software error, not a VirtualBox error on the host.

Re: Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 19. Oct 2021, 14:33
by mpack
vbicf wrote:It is working fine for what I need (small DB).
I'm not sure that the size of the database is very relevant.

Assuming that "SQL Server" means "SQL Server 2019" free download, Microsoft lists the following RAM requirements.
  1. RAM required (Express Edition): 512MB minimum, 1024MB recommended. Note that you can't possibly be giving 1024MB to SQL Server if the entire VM including OS is running out of 1GB RAM.
  2. RAM required (All Other Editions): 1024MB minimum, 4096MB recommended.
  3. RAM required (when Data Quality Server component is installed): 2048MB minimum. Not sure if this is added to the minimum.

Re: Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 19. Oct 2021, 15:44
by vbicf
OK I will try to get the log, I have to re-enable Hyper-V. I was wondering if Hyper-V would be faster than Virtulbox, I mean using VM created with the help Hyper-V instead of VirtualBox. If Hyper-V would share the GPU to the VM that would be fantastic!

Do you have any experience with VMs in Hyper-V?

Re: Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 19. Oct 2021, 17:32
by mpack
No, I have no experience with using Hyper-v VMs. I would not expect problems with performance, the usual problem with any Microsoft solution of that ilk that that they are only interested in supporting current products. Not in keeping old software alive.

Re: Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 20. Oct 2021, 13:16
by vbicf
I have some intereseting results it works on intel 7700k but not on ryzen 3800X.

I have upgraded to virtualbox 6.1.26 on both intel and amd system.

On intel it works perfectly but noticeable slower than vt-x, but I can start the old VM fine with Hyper-V enabled.

On my other system (Ryzen 3800x) I get the blue screen!

I am attaching the log from the amd system.

I have created a ticket: https://www.virtualbox.org/ticket/20621

Re: Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 20. Oct 2021, 19:20
by vbicf
I got reply to my ticket. The issue was having "Parallel Tools" installed inside the Guest! I had this VM on a mac a long time ago, totally forgot about it!

I uninstalled Parallel Tools from guest and now it boots fine with Hyper-V!

Re: Old Windows 10 VM (VT-x) but with Hyper-V activated in the host later

Posted: 21. Oct 2021, 08:20
by BillG
Lucky for you it was not VMWare PCTools! They are very hard to get rid of.