Virt-manager VM Boot Error after updates


After update, when booting Mate 20.04 with kernel, I'm taken to the grub menu then dumped into Busybox . Mate 20.04 is a VM running on Virt-manager. Host is also Mate 20.04 with same kernel. What can I do to boot the VM?

Side note, not sure if this is related but has been happening for sometime now. When I boot the host I get an error that says "error has occurred, do you want to report the problem"? Only options are "report problem" or "cancel". Where would I find the log file to see what is causing this error?


AMD 64bit with Nvidia GTX 1650 card 460.91.03 driver version

When running fsck -f /dev/sda1 at the Busybox prompt on the VM, all I get is
"fsck from util-linux 2.34". fsck is not running.

Is there something else I need to do?


Am I asking my question in the correct forum?


You seem to be asking the question in the correct forum. I think it's just that everybody who read this (myself included) either was too lazy to write a response or had no idea what the problem was. Sorry I didn't respond at the time -- but I can tell you that I've debugged a great many of these boot errors in the past, so I think I can help now.

First, simply saying that the VM drops to a Busybox prompt does not tell us much. It tells us that the system's pre-boot "initial ramdisk" got loaded, but other than that a lot of things could cause that. Do you think you can tell us the lines of context above the Busybox prompt? That's what's really useful.

Was either system's update interrupted in the middle or near the end, perhaps, or were they both smooth sailing? I would guess that the host system was updated just fine but somehow the VM crashed during its update.

Still, boot up the VM to the GRUB screen, press e, arrow down to the line that starts with linux, and remove the word quiet from the command line. Press Ctrl-x to boot the system with the modified command line, and either type as much of the output leading up to the Busybox prompt as you can see, or take a picture / screenshot of the VM when you get to the Busybox prompt.

I look forward to hearing back from you.

Gordon, thanks for the reply.

I ran fsck and have been able to boot again. However, I keep getting this error msg on the host and VM once I get to the desktop environ.
It says "System program problem detected. Do you want to report the problem?" With a "cancel" or "report problem" button. Are there logs for this somewhere that might give more details as to what is going on?


See what files are in /var/crash. This is where the crash reports are stored. If the crashes seem insignificant or something in the past, then you can delete the crash logs and you shouldn't be bothered much more.

they are all encrypted.


Oh, you mean they're not in human-readable text format. Oops. I forgot the crash logs look like that these days.

Either way, when you get the "Do you want to report a problem?" prompt, choose to show more details and at least see if you can find out what application the crash report is about. Then find that application's crash log in /var/crash and either delete it or move it somewhere else for posterity.

That's my advice.

That's the thing, there is no "show details" box to check. My only options are "cancel" or "Report the problem". In either case the error just disappears with no further clue as to what the issue is. This is happening when I initially get to the desktop and before I open any apps.

If the logs aren't encrypted, is there a way to change them to a readable format?

boot error

found the upload button.

Another thought, after running security updates that I get notified about, is it still necessary to run apt update and apt upgrade for applications that I have installed? Aren't apps automatically updated when I run security updates?

Thanks for the help.

If you mean the graphical Update Notifier / Update Manager, then I don't think you also need to run apt-get upgrade. Did you read that? "I don't think" so.

That means that I'm not sure, but I think you don't need to do apt-get upgrade from the terminal too. But I'm not an authoritative source on that, so please do not rely on my advice here.