Ubuntu 18.04 guest breaks after Ubuntu update

[jmcollins]

This is a repost of my post of a couple of days ago.

I am running Ubuntu 18.04 and VB 6.0.8 on a Xeon system, lots of processors and memory.

I wanted a guest VM also with Ubuntu 18.04 on it (I'm running a package which brings in all sorts of stuff I don't want on my host system).

I install 18.04 and it all works fine. I then apply the current updates without making any changes and when I do this the guest VM breaks - I don't get a login screen when it boots (I never set it up to do automatic login).

It's probably Ubuntu who have broken something but I'd be grateful if people could point out any errors on my part.

A log file of it being booted and then my powering off is attached.

[mpack]

00:00:03.812048 VMMDev: Guest Log: BIOS: Booting from CD-ROM...

I don't see how you can update an Ubuntu that has never been installed.

Contrariwise, if it has been installed then eject the install CD.

[jmcollins]

It has been installed, got running, checked all is working OK, then ran the updates to find that they broke it.

[SavedStates]

I got "A critical error has occurred while running the virtual machine and the machine execution has been stopped" on the reboot after the Ubuntu18 update of my guest on a Windows10 host in VirtualBox v6.0. Is that the error you ran into? My guest has been working fine for several weeks. I'm looking for a fix too.

[jmcollins]

No not quite the thing continues to run but if I press F1 something is crashing and looping rather than producing a login screen.

(I never set it to log me in automatically even on Virtual VMs I think that's super-insecure)

But there is clearly something in the updates which breaks VMs.

[socratis]

But there is clearly something in the updates which breaks VMs.

I told you in another thread that I just updated my 18.04 Ubuntu VM, and it works fine. So, please don't throw out generic statements like that.

Create a new VM and install Ubuntu 18.04, it's going to take you 10'. Then update it. Tell me if it still crashes...

[jmcollins]

Done precisely that. Results including log are in the first post in this thread.

[idunbar]

I've had the same issue. Installed 18.04 and the guest additions and it worked just fine. Ran updates and then it locked up at the login screen. If that's the issue you're having, switch the emulated graphics controller from "VMSVGA" (the default on Virtualbox 6.0.8 ) to "VBoxVGA". That solved the problem for me.

[idunbar]

Create a new VM and install Ubuntu 18.04, it's going to take you 10'. Then update it. Tell me if it still crashes...

I believe VirtualBox 6.0 (6.0.8?) uses a different default graphics controller than previous versions. If your VM was from an earlier version of VirtualBox it's probably using the other controller that doesn't have problems with the latest Ubuntu update. I think anyone installing Ubuntu LTS on 6.0.8 (using the default settings) would have the problem OP is experiencing.

[jmcollins]

Yes that definitely fixes it.

Thanks everyone.

[socratis]

If your VM was from an earlier version of VirtualBox it's probably using the other controller that doesn't have problems with the latest Ubuntu update

My VM was created with 6.0.4, but it seems that you're right; I had manually changed the vGPU from the default VMSVGA to VBoxVGA, that's why I couldn't reproduce the problem.

These kinds of problems that are reproducible, should be reported to the bug tracker. Either search for an appropriate bug, or open a new bug report where you'll attach your logs and other vital information.

It would also help if you can post the bug report number here so other can see the progress, add information, or see the final resolution.

[jmcollins]

OK thank you. I had originally thought it was more of a Ubuntu problem but I can see that isn't.

Do you want me to file a bug report now with Fixed against it?

[socratis]

Do you want me to file a bug report now with Fixed against it?

Yes, file a bug report, but remember that it's not "Fixed", it's a "Workaround". The problem *is* there with the default VMSVGA and it should be addressed sooner rather than later.

Before you do, can you please install the latest test builds and see if the latest 6.0.x test builds or the latest 6.0.97 development builds fixes it for you...