First, I'd like to thank Scott (for comment #43) and Alejandro (comment #45) - it seems there's a bunch of LP bugs orbiting around the same issue: Ubuntu isn't bootable if we set an invalid serial console on kernel command-line (and have no "quiet" option there), it seems.
Specially, I'd like to thank WGH for the great debug work on comment #46, it saved me a lot of time debugging, and you're right, it's a pain to debug issues related to console, not easy to output stuff. I used the trick to echo debug messages to the right console, helped me to narrow down some stuff. But in the end, you're debug exposed what seems to be the major problem here: due to a return value carriage among functions (starting with printf returning 1 due to bad console), we end up looping in checkfs(), preventing the boot. I respectfully disagree with Scott: although I consider there are potential improvements on kernel in the console "front", we have here a userspace bug in init scripts, due to an error in printf if console is not correctly set. I don't agree we should let it alone and pursue a kernel-only solution, specially due to the easy nature of reproducing the issue, and hard nature of debugging it. Also, it seems there are long-term bugs reporting similar issues, it bothers a bunch of people. I cannot be 100% sure we don't have more issues than the checkfs() one found by WGH, but this one is definitely an issue and an easy one to fix; I proposed a pretty simple fix in the below test-only PPA: https://launchpad.net/~gpiccoli/+archive/ubuntu/lp1573095 The more users can test that, more confidence we'll have that there are no more initramfs bugs if console is wrongly set. I agree with the idea of showing some output message on kmsg if serial console is broken, it's helpful. We can do that as part of an improvement, maybe in the same "commit" as the fix. More opinions are welcome on this matter, of course. If my solution either doesn't resolve the issue for users or is not the optimal one, let's discuss alternatives to fix this initramfs long-term flaw. Thanks, Guilherme -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1573095 Title: Cloud images fail to boot when a serial port is not available To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-images/+bug/1573095/+subscriptions -- ubuntu-bugs mailing list firstname.lastname@example.org https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs