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Ubuntu 20.04 stuck on black screen after boot and Ubuntu logo

Posted: 9. Apr 2022, 04:56
by tinyLizard
Hello!

Up until the previous time I booted up this VM, I had no problems running it.
However, now my Ubuntu 20.04 VM gets stuck at a black screen after the Vbox and Ubuntu logo screens.
I'm not sure what changed that caused this to start happening. Is there something that can be done to fix it?

The log is attached.

Virtualbox version is 6.1.32 r149290

Re: Ubuntu 20.04 stuck on black screen after boot and Ubuntu logo

Posted: 9. Apr 2022, 10:33
by mpack
The log you provided is the hardening log, and even that is not complete - you have to shut down the VM before copying out files.

After shutting down the VM, zip the file "VBox.log". Attach the zip here.

Re: Ubuntu 20.04 stuck on black screen after boot and Ubuntu logo

Posted: 10. Apr 2022, 10:29
by tinyLizard
Thank you for looking into this and for the response! I was able to fix it in the end, but I will remember that the next time I run into a similar problem.

After giving up on comprehending the log, I tried the other options available to me- I was able to fix it by toggling the below options in Virtualbox.

Under the View tab (Fixed while the VM was runnning):
Disable Auto-resize Guest display
Under Virtual Screen 1: Resize to 1900x1200 (Had been originally Resize to 640x480 by default)
Scale to 100% (unscaled output) (Had been originally Scale to 200%)

Re: Ubuntu 20.04 stuck on black screen after boot and Ubuntu logo

Posted: 10. Apr 2022, 13:16
by mpack
Thanks for reporting back, unfortunately I have doubts whether any of the settings you mention would have had a direct effect. It would be different if you increased the graphics RAM, as setting that too low (e.g. the default of 16MB) has definitely been known to cause graphics problems including a black screen.

Auto-resize is usually best enabled. It's hard to see how having it turned on could stop the guest OS from booting into a GUI: though it's possible you stopped the VM from switching to a graphics mode it didn't have enough graphics RAM for.

Your last two settings changes don't seem right to me.