[Solved] Critical Error after updating guest machine

[Zed001]

After updating the guest machine, on next opening have received a critical error and machine execution has stopped. Would appreciate any help as to what to do next. The attached is the log file from the event:

[mpack]

00:00:08.082949 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
00:00:08.082951 !!
00:00:08.082951 !! Guru Meditation 1155 (VINF_EM_TRIPLE_FAULT)
00:00:08.082963 !!
00:00:08.082994 !! Skipping ring-0 registers and stack, rcErr=VINF_EM_TRIPLE_FAULT
00:00:08.083001 !!
00:00:08.083001 !! {mappings, <NULL>}
00:00:08.083002 !!

Means that the guest did something nasty. Make sure AMD-v is available, as that will eliminate most such faults. You should also upgrade to a supported version of VirtualBox, e.g. the current release (5.2.12).

[Zed001]

AMD-v was enabled. I upgraded to 5.2.12, but still the same problem. Other virtual machines run fine, it is just the one that causes the error. The updated log file is attached. Appreciate any other thoughts.

Thanks

[mpack]

If other VMs work, especially similar ones, then I can't think of what could be wrong with VirtualBox to explain this. So the only thing that springs to mind is corruption of the boot drive. Basically an attempt to run random code. Do you have a backup of this VM? Is the drive readable as a non-boot drive in another VM?

Edit:  Hmm. The last thing the VM does before the error is a long series of display resizes, so I look back to see what your graphics setting are.... and graphics RAM is horrifically low, only 12MB. Did you say that this VM was previously working? I don't know why you have VRAM set so low - surely the VM settings dialog is warning you about this? Anyway you have plenty of RAM so I'd shut down the VM and change this to 128MB. While you're at it I'd also assign 2 cores to the VM.

[Zed001]

Tried both your suggestions, and no change. While I was downloading the instance to a new machine, it occurred to me to try booting to an earlier kernel in the guest, and once I rolled back around 20 or so, it booted up fine. I'm certainly not an expert at this, but would think likely that one of the recent guest OS updates somehow borked the OS, given an earlier version works. In any case, I'm able to get what I need out of the guest system and can construct a new instance, so I'll head down that path.

Thanks for your help - I wasn't aware I was starving my guests of resources, so will be more mindful as I set up new instances.

[socratis]

the guest machine ... Other virtual machines run fine, it is just the one ... downloading the instance to a new machine ... an earlier kernel in the guest ... recent guest OS updates ... an earlier version

You never mentioned what the guest is, what updates you refer to, from which version to which version. All generic references. Can you use specifics and details?

Oh, and because this seems to be a guest-specific problem (the underlined text), I'm moving this to "Linux Guests" from "Linux Hosts".

00:00:00.570035 File system of '/home/ron/VirtualBox VMs/PeppermintLarge/Snapshots' (snapshots) is unknown
00:00:00.570052 File system of '/home/ron/VirtualBox VMs/PeppermintBig/PeppermintBig.vdi' is ext4

It seems that you created a new VM and used an existing VDI from another VM. Correct? Why? And given the name (Peppermint) I think that my previous question is answered, that you are talking in fact about Peppermint OS. Still need the details, versions, etc. though.

00:00:00.627717 VRamSize <integer> = 0x0000000000c00000 (12 582 912, 12 MB)

See mpack's comment. And while you're at it, enable 3D acceleration in the same Display settings.

[Zed001]

Thanks all. Using your suggestions along with going back several kernel versions, I was able to open the guest, where I was able to extract the necessary data and software settings needed. I then created a new guest machine using updated OS and software, and incorporated your suggested settings for a guest machine.

That's all I needed - for my needs this is solved.

My apologies for dragging you through something which appears to have been caused by a combination of my poor practice and possibly some guest OS update issues. I'm having no problems with the latest version of virtualbox nor with the new guest nor any of the other old guests.

Cheers

[mpack]

Thanks for reporting back.