Kernel Panic - root device not found after upgrade from 20.04 to 22.04

[Markus]

Ubuntu Support Template

Ubuntu Version: 22.04 LTS server

Problem Description:
I hasitated to upgrade my Ubuntu 20.04 server due to mailman, but now I decided it is high time to upgrade my 20.04 to 22.04. Therefore I did an final clean dist-upgrade in 20.04 and rebooted.
Afterwards, I did an do-release-upgrade with also seemed to run fine as normal.
But afterwards, the system did not come back due to a “kernel panic” by rebooting. The issue is, the UUID given is existing, but the one of an part of my MD-Based software Raid1. I also tried boot repair from a repair session, also this seemed to run fine. Unfortunately, the forum link given there does not work any more (Boot-Repair - Community Help Wiki ) - but I have created the debug info from that: Boot-Repair - Community Help Wiki
Now the boot is worse, it just remains in a black screen - but I still can edit the boot parameters in grub.
Otherwise, I attach the screenshots. Sorry for the quality, as it is a remote server I only have a KVM with limited video quality.
The other screenshots show the details of the UUIDs of the MD-Software-Raid.

[rubi1200]

Welcome to Ubuntu Discourse

We really need to see the boot info summary if possible.

The link to the community wiki seems to be working.

Choose the option to run the summary and not the repair, then paste the link to the pastebin back here in your reply.

Hopefully, it will give us some clues.

[Markus]

Thanks to the feedback. I started the boot-repair tool again and selected to create the boot info. But his his now running for hours - the message is “Crate a Bootinfo summary (bis). This may take several minutes…” - I guess it is deadlocked, even though a blue scrollbar is running below from left to right and vice verse.

[rubi1200]

Normally, running the script only takes a few seconds.

Can you try these commands and post the output (best to copy the terminal output and paste here rather than use screenshots, if possible):

lsblk -f

cat /etc/fstab

[Markus]

Yes, of course:

# lsblk -f
NAME    FSTYPE FSVER LABEL UUID FSAVAIL FSUSE% MOUNTPOINTS
loop0                                          
sda                                            
├─sda1                                         
│ └─md0                                        
├─sda2                                         
│ └─md1                          216,5M    50% /boot
├─sda3                                         
│ └─md2                          408,7G    36% /
├─sda4                                         
└─sda5                                         
sdb                                            
├─sdb1                                         
│ └─md0                                        
├─sdb2                                         
│ └─md1                          216,5M    50% /boot
└─sdb3                                         
  └─md2                          408,7G    36% /
# cat /etc/fstab 
proc /proc proc defaults 0 0
none /dev/pts devpts gid=5,mode=620 0 0
/dev/md0 none swap sw 0 0
/dev/md1 /boot ext3 defaults 0 0
/dev/md2 / ext3 defaults 0 0

[Markus]

Thanks for the feedback, but I need the server back, so I have decided to reinstall it.

[rubi1200]

Sorry I was not able to help more with this issue.

RAID arrays are not my area of expertise at all.

If you have good backups, a reinstall is often the quickest way to deal with the situation.