Linux Mint doesn't boot after upgrade to version 21

[Metagross31]

Hey everyone,

Yesterday I upgraded my system from Linux Mint 20.3 to 21 using the `mintupgrade` tool.
When trying to reboot after the upgrade was done, the system did not manage to fully boot. I got to the point in the boot process, where the mint logo shows up and by pressing the delete key one can see more info on what is going on. There it got stuck though, after saying that a lot of things failed (e.g. starting network manager and several other things. I can try to take a picture of it with my phone if needed.) for over 7 minutes, telling me that some process was on hold until boot is finished (again, I can take a picture to show the exact wording) which was the point where I gave up on just waiting.

Today I used the repair-boot tool from a live USB image, the summary can be found here: http://sprunge.us/mdSkc4
But still, the same exact problem continues to happen.

As it might be an important piece of information: I upgraded the exact same system, where I had to change the booting location from one disk to another as explained in this thread: viewtopic.php?f=46&t=371106

Any ideas what could have gone wrong and how to fix it?



EDIT: Here are the screenshots:
https://imgur.com/a/46dycQH
I also added a short description under each image.

[SMG]

Yesterday I upgraded my system from Linux Mint 20.3 to 21 using the `mintupgrade` tool.

Were there any messages at the completion of the upgrade?

Today I used the repair-boot tool from a live USB image, the summary can be found here: http://sprunge.us/mdSkc4
But still, the same exact problem continues to happen.

This output seems to indicate you need to:
"Please do not forget to make your UEFI firmware boot on the Linux Mint 21 Vanessa (21) entry (nvme0n1p1/efi/ubuntu/grubx64.efi file) !"

Here are the screenshots:

One of the failures is the failure to start LightDM. That means you will not have graphics. It seems the system tries multiple times and many of the failures are repeat failures (so not as many failures as it might seem at first glance).

Those failures happen after fsck is done. fsck checks for system integrity.

Did you take a Timeshift snapshot of your system before you did the upgrade? Based on what I see in the screenshots, I'm not sure the upgrade completed properly.

[SMG]

Moderator note: guyr's post can now be found here Linux Mint doesn't boot after upgrade to version 21 because upgrade issues are unique to each install. Please do not add your issues to someone else's topic.

[guyr]

I'm not following why you elected to move my comment into its own thread. The symptoms I'm experiencing are very similar to the ones the OP described. That's why I added my comment here. Grouping multiple reports of the same issue help to understand the commonality of the problem. The solution to both our situations may be the same. By splitting these reports up, we end up with duplicate reports, and make it more likely that people might miss the solution posted in one place but not the other.

[SMG]

I'm not following why you elected to move my comment into its own thread.

To comply with forum rules which you agree to follow as a forum member. Many problems can have similar symptoms coming from different root causes. You are running Linux Mint in a VM. This person is not. Therefore, your circumstances are different.

There are already many topics on this forum of people have run into issues with Linux Mint not booting after upgrading including ones which are now marked solved.

[guyr]

Ok, thanks for the explanation. I made further progress. I'll continue in that other thread.