[Solved] Virtualbox-Xubuntu 18.10 Error

[ergo]

Hello,

whenever I try to install Xubuntu 18.10 (Cuttlefish) ) as a guestsystem
within the newest version of Virtualbox (5.2.22) the install process runs fine at first.
After the necessary reboot the Virtualbox window gets streaky and Virtualbox
freezes and works again after a hard reset only.
This happened using 32 or 64 bit version of Xubuntu 18.10.
Xubuntu 18.04.1 however works fine in Virtualbox.
My host system has to be OS X Sierra for a while.
I tried different options for memory and other preferences - nothing helped.
Are there any hints about the reason? A driver problem perhaps?
Any solutions?

Thanks for help.

[socratis]

We need to see a complete VBox.log, from a complete VM run:

• Start the VM from cold-boot (not from a paused or saved state) / Observe error / Shutdown the VM (force close it if you have to).
• With the VM completely shut down (not paused or saved), right-click on the VM in the VirtualBox Manager and select "Show Log".
• Save only the first "VBox.log", ZIP it and attach it to your response. See the "Upload attachment" tab below the reply form.

[ergo]

Vielen Dank socratis für die Antwort.
Anhängend lade ich wie vorgeschlagen die gezippte 1. Logdatei der Virtualbox hoch.

Für weitere Hinweise und Hilfe wäre ich dankbar.

[socratis]

00:00:11.976683 VMMDev: Guest Additions information report: Version 5.2.18 r123745 '5.2.18_KernelUbuntu'

You have not installed the Guest Additions (GAs) that come with VirtualBox, you have still the ones that came pre-installed with Xubuntu. You need to uninstall the existing GAs and install the VirtualBox ones.

[ergo]

Thank you socratis for your reply.
How should I manage to install the guest additions in this case?
All I can see after install of xubuntu and reboot is very similar
to a streaky dark screen. And yes the guest addition isofile is connected to Controller:IDE of the machine as a secondary master, but obviously that doesn’t solve the problem. I tried to change the preferences for this to the primary and secondary slave options - again no success.
As told already the install process works fine at first. The problem with the screen occurs always after reboot.
And what is remarkable virtualbox sometimes freezes or even crashes what never happened with Xubuntu 18.04 as a guest until now.
So what can I do to solve the problem? How can I install the corresponding guest additions 5.2.22 in advance to avoid the screen problem after reboot?

[socratis]

It took me 1 hour to figure out what's going on! You owe me 1000 € !!!
Shut down the VM. Open Terminal and give this command:

• VBoxManage modifyvm "xubi1810" --graphicscontroller vmsvga

"xubi1810" is the name of your VM according to the logs, if you've renamed the VM, adjust accordingly. Let me know how it goes...

[ergo]

Socrates thank you very, very much for your intensive research and help!
Using VBoxManage to change the graphiscontoller to vmsvga works - great!
During the boot process the box window gets temporary partly streaky, but login is possible.

Another problem occurs now: The screen resolution is fixed to 800x600 and can’t be changed, though guestadditions are obviously installed.
My idea was that the default option for graphicscontroller might be the vga option and I tried
VBoxManage modifyvm "xubi1810" --graphicscontroller vboxvga
assuming this might be like a reset to the original preference and could work now meanwhile having guestadditions installed.
Obviously this is a misconception, because now the boot process stops before the login window and a dark screen appears instead.
Setting back to svga again works, but the minimized resolution makes it difficult to use the guest system.
In a virtualbox command list I didn’t find any other options for the VBoxManage command than none, vboxvga, and vmsvga to change graphicscontoller setting . So I am at a loss how to make the resolution preferences adjustable again
with xubuntu 18.10.

[socratis]

The screen resolution is fixed to 800x600 and can’t be changed, though guestadditions are obviously installed.

I had to do the whole installation again. That's 2000 € you owe me now in support charges!
Even with no GAs installed, I was offered a gazillion of resolutions. How exactly did you try to change the resolution? I simply went to Settings » Display » Resolution. Picked up my favorite 1280x1024, clicked Apply and... done. Where are you looking at?

[ergo]

Socratis many thanks for your help!

Well, I saw the different options of screen resolutions too. But they were grayed, moving the mouse over to scale factor and back over them they got black - but couldn‘t be checked.
So the resolution remained fixed to 800x600.

As I got an undefined system error message I ran a reinstall of Xubuntu 18.10 but now before doing so I changed graphicscontoller to vmsvga by the VBoxManage Command.
This worked and I got the login this time directly, but the resolution problem remained of course.
After that I ran the VboxManage Command again to change graphicscontroller to vboxvga, because this might be the default setting.
Now the reboot ran fine without any display problems and the resolution options could now be checked as usually.
So the problem is solved – but its reason remains unclear for me.

So again thank you very, very much for your advice.
Of course your posted VBoxManage command to change graphicscontoller was the royal road
to success.

[socratis]

I saw the different options of screen resolutions too. But they were grayed, moving the mouse over to scale factor

Please tell me that you were not trying this whole time to change the resolution from the host, were you? Oh, for the love of bytes! Why didn't you try to change it like any other OS? From inside the OS?

Of course your posted VBoxManage command to change graphicscontoller was the royal road

And that's actually what took me more time to find, and what made it interesting for the developers, that a freshly installed OS would actually require the VMSVGA option to be there.

Really glad you got it going, marking as [Solved].

[ergo]

Thanks for your reply, socratis.

Please tell me that you were not trying this whole time to change the resolution from the host, were you? Oh, for the love of bytes! Why didn't you try to change it like any other OS? From inside the OS?

Though the problem is solved let me please explain this at the end.
Sad to say I didn’t guess it, didn’t know it because I never needed it, so I never
searched for it until now how to do.

Meanwhile I know the xrandr -s command to change it from the inside of Virtualbox.
Probably your comment appeals to that, I suppose.

[socratis]

Generally speaking, I prefer to do things from within the guest, not "surprise" the guest with something that's happening on the host. There are less chances of something going wrong, because... the guest knows best.