[SOLVED] Mint 21 install fails to boot

[Arch4751]

Having searched this forum and Google for clues and found nothing to parallel my experience,, I resort to this community for answers.
With the promise of compatibility with my Epson scanner, I downloaded LM 21 Vanessa on an HP Spectre laptop to replace LM Cinnamon 20.3. Used the new upgrade tool to install on the internal ssd. All good according to the installer. Reboot... no way. Grub appears and offers choices... 1. Linux Mint 21 Cinnamon 2. Advanced options for Linux Mint 21 Cinnamon 3. UEFI firmware settings. Says it will automatically go to highlighted option (1.) in 25 sec. It then goes to "Error, out of memory, press any key to continue". Press the key: screenful of output text ending in " end Kernel panic - not syncing: vfs: Unable to mount root fs on unknown-block (0,0) .
Whichever option for boot is offered, all roads lead to this screen.
Confession: Not really relevant, but as a backup, I created a live usb version using Rufus but I didn't verify the iso. due to several successful installations of earlier versions without verification, and of course didn't adjust boot order, expecting the internal installation to hold. So....
Where to next? My wife has her stern eye on my progress...it's her laptop.
Please be gentle...I'm old and tired.
I LOVE the clean efficiency of Linux and the whole open source philosophy of a co-operative community... an oasis in an increasingly, hysterically
cacophonous commercial world. Please don't make me go back.
Any Terminal instructions need to be very complete...I'm still green, in many ways.

[gittiest personITW]

Do you have a backup of the files/docs/pictures/important data?
Not talking about the imaged drive but a separate backup.

If so, just do a clean install. Upgrades in general aren't 'clean' and can make it very hard to see what a problem might be.

Can you still boot into your old installation?
If so, an inxi report would be handy - see number 5 in the following link:
http://forums.linuxmint.com/viewtopic.php?f=17&t=83444

Also follow the instructions here to re-copy the iso:
https://linuxmint-installation-guide.re ... /burn.html

[karlchen]

Hello, Arch4751.

Welcome to the Linux Mint forum. And sorry that you ran into this really bad bug.

In advance:

From my point of view, your best choice is returning to Linux Mint 20.3 Cinnamon and staying with it, until the underlying root cause has been resolved by the Ubuntu developers.
In case you created a Timeshift snapshot, before starting to upgrade Linux Mint 20.3 Cinnamon (una) to Linux Mint 21 Cinnamon (vanessa), you should use Timeshift and restore to that snapshot.

On Grub "Error, out of memory, press any key to continue":

Frequently, this happens already when booting the USB live & installation medium. See e.g. this Askubuntu support thread, Ubuntu 22.04 Live USB fails, reports "Out of Memory" with no details, even after working on other machines

When it happens after an in-place upgrade from Mint 20.3 to Mint 21, then a frequent trigger is that the system uses the proprietary Nidia graphics driver software.
Does your machine have an NVidia graphics card? If it has, did you use the proprietary NVidia graphics driver software on Mint 20.3?

The underlying root cause seems to be inside Grub. Grub seems to have a memory limit, which prevents it from allocating more than 2 GiB of memory. In cases when proprietary NVidia drivers are in use, Grub would need more than 2 GiB of memory, but cannot allocate it.

There is a Launchpad bug thread about this problem: Bug 184320 - Can't boot: "error: out of memory." immediately after the grub menu

Both, the linked Askubuntu thread and the Launchpad bug report, hold workarounds for different scenarios, under which the bug may strike.
But:
From my perspective all these workarounds are pretty tricky. And no normal user can be expected to identify the right workaround and follow the appropriate steps. (My point of view)


Summary:

Revert to Mint 20.3 Cinnamon and stay with it, either until Mint 20.3 reaches the end of its supported life. Or at least, until the developers, who maintain Grub, have managed to resolve the "out of memory" problem reliably.

Best regards,
Karl

[Arch4751]

Thanks Gittiest,for your quick response and suggestions.
No, I don't have an external backup, only Timeshift...is it possible to access that from grub? Also, is it possible now to boot (and install) a live usb version of lm 20.3 and access existing files or are they necessarily lost? I haven't looked at links provided by you and Karlchen yet...they may answer these questions. Don't know which graphics card is there..I inherited the laptop from my daughter and never needed to know.
If push comes to shove I'm prepared to lose the data to restore functionality. The path of least resistance is appealing.
And thank you Karlchen for your response...I'm always hopeful but still pleasantly surprised by the willing hands here. I'll now check the linked material for further insights. Little by little, understanding will come. I'll post results in the next 24hrs. I'm a slow worker.

[Arch4751]

Well, well well...how easy was that. I took the path of least resistance...the nuke option (clean install via Rufus + iso on usb drive). I had hoped there was a possibility of accessing and rescuing data, but you weren't exaggerating, Karl, when you opined that the work-arounds were too complex for ordinary mortals; I had a peep at the Launchpad bug thread on this topic...I remain amazed at the power of some human minds. With more patience I suppose I could have pursued the Timeshift path, and for future understanding, I'd like to get my head around the idea. However on this occasion our data was not of critical value and a fresh start always feels good.
Gentlemen, I thank you again for talking me through the issue...I imagined it would be more difficult.

[gittiest personITW]

Glad you managed to sort it out.
RIP your data.

Just to push the idea though, there really should be backups on external/removeable drives
(Multiple) for anything that you don't want to lose. Anything not backed up should be considered lost.

[Arch4751]

Roger that Gittiest. Sometimes I have. Sometimes optimism rules. I often learn lessons the hard way.

[gittiest personITW]

Those are the lessons that we don't forget.