virtualbox.org

I have used virtual box for many years without issue. My current host machine (32 GB ram, i7 9750H on Windows 10 Pro) started having a number of issues. My existing linux virtual machines would have errors updating, existing and new ones will freeze during use / install or have boot issues getting to the desktop. Its odd I'm providing plenty of resources (12 gb ram, 128mb video memory, 4 cpus, etc). I'm unclear how to troubleshoot this but I have tried a good 4 or 5 distros that ran fine in prior setups, so I'm nearly ceratin something is wrong with my configuration. Any ideas how I could go about troubleshooting this? I have updated to the latest virtual box, should I uninstall reinstall or is there a good way to reset everything to default, perhaps I configured something from the terminal / otherwise that borked it.

Pick one guest. Start the guest from full normal shutdown, not save-state. Run until you see the problem happen, then shut down the guest from within the guest OS if possible. If not possible, close the Virtualbox window for the guest with the Power Off option set.

Right-click the guest in the main Virtualbox window's guest list, choose Show Log. Save the far left tab's log, zip it, and post the zip file, using the forum's Upload Attachment tab.

Okay so I just tried with popos, it seemed to intsall relatively okay, I installed guest additions and restarted, that went fine too. Then I tried running software updater and it failed. Then I tried sudo apt-get update and that failed with a message about hash mismatches (something I started getting on all ubuntu based VMs) then I opened firefox and the system crashed. Crash log attached. I'm very puzzled what is wrong here, maybe my log will show something to someone with a keen eye for what to look for. Thanks.

Your log contains these lines:

{timestamp} HM: HMR3Init: Attempting fall back to NEM: VT-x is not available
{timestamp} NEM: WHvCapabilityCodeHypervisorPresent is TRUE, so this might work...

You might notice in the guest window's Status Bar the green turtle: The choice of animal is appropriate: Your guest is running, just really slow. Or it might guru-meditate. This is because a service that uses Microsoft Hyper-V is running on your host PC. Normally Hyper-V blocks Virtualbox. But your PC is of the type and OS where Virtualbox can attempt to run the guest using the Hyper-V engine. This arrangement is still being developed and isn't 100% yet.

If VirtualBox is running without Hyper-V enabled, and nothing else is interfering with hardware virtualization (VT-x / AMD-V), then the usual virtualization icon () will be seen in the Status Bar.

To turn Hyper-V off completely, do this:

1. Shut down all programs. You will have to reboot your host.

2. See I have a 64bit host, but can't install 64bit guests. This tutorial has a couple more things to look for in step 2. Be sure these are all turned off.

3. Find the Command Prompt icon, right click it and choose Run As Administrator.

4. Enter this command:

bcdedit /set hypervisorlaunchtype off

5. Enter this command:

shutdown -s -t 2

6. When the computer turns off, unplug it for 20 seconds. Then plug it in again and boot up Windows 10.

If your Virtualbox does not start successfully, zip and post another vbox.log. For further info, see https://www.tenforums.com/tutorials/139 ... puter.html

Thanks for this info, so if I understand I must disable Hyper-V to get performance / usability back? I use docker and wsl, I think they may use hyper-v, perhaps I can't have them all happily run together? Will try this soon.

To get Virtualbox going again, yes, you must disable Hyper-V. The sticky at the top of Windows Hosts: "VirtualBox 6.0 and Hyper-V" shows some folks results running with Hyper-V enabled. Maybe a particular setup is required?

Note the tenforms link, it has a tutorial for an at-boot switch to toggle Hyper-V.