VBox fails to run Linux guests

[Leris]

Hey all,

not sure how to best describe the problems I'm facing.

So first off, I was using Virtualbox for years really without any problems.

I had a Linux Mint 18.3 64 bit guest installed and it just worked fine as expected.

Then some day after I updated some Linux applications, updated Virtualbox itself as well, things went awry.

The box will start alright, but then run into lots memory errors. They either show in random places Linux, like some established apps not even starting, which I had been using without problems, or even the box itself crashes hard.

I then went on to install a fresh Mint 20 alongside. Installation went fine, but after the first boot, the Cinnamon window manager claims some crash happened, and I am dropped to a nearly bare desktop. Also, other applications claim memory errors.

This was all with Virtualbox 6.1.10 - I then took a bit pause out of desperation on how to remedy.

Now with Virtualbox 6.1.12 I tried installing another Mint 20 guest, but can't even complete installation from the CD image due to memory errors.

I would welcome some advise on how to continue. At best I'd like to continue using the Mint 18 machine, as it's all configured already, but at this point I don't mind setting up a new Mint 20 guest, just to have it working.

As it seems now, the problem shows in many different places and forms, and I have no idea which details to show to you, or how to solve this mess.

Please advise. Thanks in advance!

[Leris]

OK so I was asked in chat to show some screenshots, because nobody understands exactly what I describe. Seems like this is a rather unique problem for me then?

I am not really sure how easy this will be to follow, because it is German and can be very app-specific, but there's a great one at the end, I guess everyone can agree...

Please do let me know any other commands or programs I can try to display more of what may be going wrong here!

Exhibit A: Mint 18 (old from earlier)

Login screen seems as expected:
https://i.imgur.com/ZKAJ7hG.png
I can wait here a number of minutes without anything unexpected happening.

Max. 2-3 max. after startup completed, mostly after pushing the mouse or clicking:
https://i.imgur.com/dSjoUwQ.png
Roughly translates to "Cinnamon crashed. You're in Fallback mode. Want to restart Cinnamon?"
Restarting will just repeat the cycle.

Trying to start the "Mudlet" application (which had been working flawlessly for months and years)
https://i.imgur.com/HMejoYb.png
Roughly translates to "Bus access error (memory copy written)"
I guess hardly anyone knows this application, but it's just one example really. It's written in C++ if that matters.

Another application regularly failing is the Mint updater, which fails to even download the requested files. (no matter which application should be updated) (but it is online alright)

Trying to shut down the machine (by clicking "shutdown" in menu)
https://i.imgur.com/WXt0lO0.png
gnome-keyring-deamon is still running but does not answer.

----

Exhibit B: MInt 20, installed fresh after noticing above

Right off the bat, after installation completed and machine restarted, the same Cinnamon crash occurs:
https://i.imgur.com/JSOCwTN.png
There is more text, but it basically says the same as above: "Fallback mode. Want to restart?"
You can set a checkbox here now, but it does not change anything, will still repeat the cycle.

-----

Exhibit C: Mint 20, installed once again for good measure

This even fails during installation. In fact, it hadn't even begun. This is from live CD version while asking for my name and computer name, as preparation for the installation:
https://i.imgur.com/G2NxWMr.png
"Error whily copying files to local drive" and "May be due to corrupt CD drive, medium or hard drive" - Note all of these were also used flawlessly for installation of exhibit B.

Another error (this time in English yay) after vouching to install multimedia codecs as part of Mint as well:
https://i.imgur.com/uA2Eayq.png
"ubi-partman failed" - the whole Installation fails here, could not be completed.

-----

Exhibit D, back in the Mint 18 machine

This time I didn't start Mint at all, instead started Memtest86+ directly from grub:
https://i.imgur.com/lCnAqxo.png
Result after 2 hours: 140,000 errors, 0 pass..! This is literally scrolling red lines nonstop!

Same test ran on further:
https://i.imgur.com/NEBMrK9.png
Result after 3 hours: 180.000 errors, 0 pass...!


For good measure, I also ran memtest on the host. There were exactly 0 errors there.
(no screenshot)
Also I only get reports like this inside the guest, never on any other host applications.


As additional bonus, here is some syslog for you, as I heard this may help as well:
https://i.imgur.com/33UIwSD.png
https://i.imgur.com/PM85F2f.png
https://i.imgur.com/cPosJp2.png

[scottgus1]

A guest vbox.log, zipped and posted using the forum's Upload Attachment tab, would be much more useful.

Please 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 and needs to be disabled. See HMR3Init: Attempting fall back to NEM (Hyper-V is active). (The new test builds might have a fix for this problem. If you try a test build and it works, report here: viewtopic.php?f=6&t=90853, and save the installer file.)

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.

[Leris]

Thanks scottgus1 for the guidance! Your assumption was 100% correct. I find this line in all 3 machines' logs. Will review your linked thread and test builds now.

[Leris]

I tried the most current test build, but it did not work. Should I report there, too?

Will try disabling Hyper-V now, hoping it is not required elsewhere after all.

Also, my machine won't boot up anymore, instead show this screen output:

https://i.imgur.com/3VLmpi8.png

edit: This happens also without the test version. Strange!