I've been running systems up to Buster and have always had the 'quiet' option in the grub settings to show the regular service startup messages (the colored ones showing [ok] and such but not all the dmesg stuff). I just upgraded a server to bullseye and there are zero messages being displayed now except an immediate message about not being able to use IRQ 0. Worse, google can't seem to find any information on this. If I remove the quiet option from grub then I see those service messages again, along with all the other stuff I don't need.
What is broken and how do I fix this issue? I assumed it would be safe to upgrade by now but this seems like a pretty big problem if I ever need to troubleshoot a system.
[Edit] In case anyone else finds this post searching for the same issue… Apparently the trick is that now you MUST install plymouth, even on systems that do not have a desktop environment. For whatever reason plymouth has taken over the job of displaying the text startup messages now. Keep your same grub boot parameters (quiet by itself, without the splash option) and you will get the old format of startup messages showing once again. It’s been working fine the old way for 20+ years but hey let’s change something just for the sake of confusing everyone.
[Edit 2] Thanks to marvin below, I now have a final solution that no longer requires plymouth to be installed. Edit /etc/default/grub and add systemd.show_status=true to GRUB_CMDLINE_LINUX_DEFAULT. In my case to full line is:
GRUB_CMDLINE_LINUX_DEFAULT="quiet systemd.show_status=true"
Don't forget to run update-grub after you save your changes.
So unfortunately, no, an older kernel didn't change what is happening. I would guess that reinforces my believe that it's a system setting which was changed rather than a kernel issue?
As far as upgrading to bookworm... this kind of thing is exactly the reason why I never run the current release. I literally just installed stretch from scratch (because I couldn't get a buster image to boot on this machine), dist-upgraded to buster, then when everything looked good I decided to go ahead and push it to bullseye. Nothing else has even been installed yet, the only change I made along the way was forcing all six network ports to the expected names (first using the grub and udev settings, then under bullseye I had to add files under interfaces.d). It's a clean system, apt didn't even have to ask me for permission to change any config files during the upgrades, which is the reason I immediately assumed this was a debian problem.
Regarding dmesg, I'm not sure what I should be looking for? Everything boots up fine, it's just that the system is not displaying any of the expected startup messages now. It doesn't seem like a system problem, more like an issue with the function that displays these messages is no longer outputting anything to the console.
Try upgrading or reinstalling.
(Just realized your system isn't down.)
Bookworm should fix the issue.
(Know that there's some bullseye -> bookworm hicupps.)