virtualbox.org

This is my first post on this forum,

so sorry in forward for any violation of community rules.

I've created from an old and running WinXP machine a VDH file with the disk2vhd tool. I managed to get the VHD running on my Win10 64 pro system, but failed to get a clone of that running on the laptop of my sister (as well Win10 64pro, 4/8 cores/hyperthreads, 16Gb ram). It seems that, when the windows guest is finally is trying to start the windows-gui, the boot process crashes (black window, sometimes with blinking cursor, sometimes not...). Any clues, hints or tricks would be appreciated! I have tried to create log files of the two different host machines and put then into a zip file as an attatchment. I hope everthing went well...

Sorry for any grammatical hicups, since my native language isn't english.

Cheers

donkiel

The "crashing" log was the VM's hardening log, not the vbox.log, like the "running" file was, so we can't see immediately what the problem is.

However, with a Windows host it's likely Hyper-V enabled on the laptop.

Right-click the guest in the main Virtualbox window's guest list, choose Show Log. Search the far left tab's log for this text:

Attempting fall back to NEM

If you find it, Hyper-V is enabled. You have two options:

1. Try the 6.1.35 test build. Save the test build installer until you update again later. You'll need it if your host's MSI installation database goes south (they do) and the installer will not be available for download after the next even-number version gets released.

2. Turn off Hyper-V. See HMR3Init: Attempting fall back to NEM (Hyper-V is active).

If you don't find that text, save the far left tab's log, zip the log file, and post the zip file, using the forum's Upload Attachment tab.

Attempting fall back to NEM

If you find it, Hyper-V is enabled. You have two options:

1. Try the 6.1.35 test build. Save the test build installer until you update again later. You'll need it if your host's MSI installation database goes south (they do) and the installer will not be available for download after the next even-number version gets released.

2. Turn off Hyper-V. See HMR3Init: Attempting fall back to NEM (Hyper-V is active).

I've found the mentioned text in the log, but it tells that VT-x-is not available. Similar problem?? I don't know if VT-x is dissabled in the BIOS, but since I have only remote access to my sisters laptop I can't check it right now. Anyway, I send the the proper log file as an attachment.

00:00:04.372439 HM: HMR3Init: Attempting fall back to NEM: VT-x is not available

Thank you for your almost immediate answer. I appreciate that very much!
donkiel

EDIT: I've just realised, that the WinXP guest is in fact not crashing, but running really, really slow. The green turtle icon is on 100%, so maybe VT-x is the real issue . Anyway, I would wellcome you to have a second look on the new log.

The log contains the telltale lines:

00:00:04.372048 ********************* End of CFGM dump **********************
00:00:04.372439 HM: HMR3Init: Attempting fall back to NEM: VT-x is not available
00:00:04.441939 NEM: info: Found optional import WinHvPlatform.dll!WHvQueryGpaRangeDirtyBitmap.
00:00:04.442005 NEM: WHvCapabilityCodeHypervisorPresent is TRUE, so this might work...

This indicates that VT-x is available, but something (usually Hyoer-V) is blocking the access that VirtualBox needs for best performance.

So, the options you currently have are as previously stated by Scottgus1 in his preceding message.

OK, understood...

I will have a look on the Hyper-V issue. Thanks for your advice, I'll report, if/how the issue was solved (or not.... )
At least I know to generate a proper log file