[Bug 705150] Re: Hang trying to enter single-user mode (runlevel 1)

[Bruno Nova]

I also discovered this issue (or something similar) in Ubuntu 14.04.
This is an old bug, but I will comment here instead of reporting a new bug.

When I run "sudo shutdown now" or "sudo telinit 1" to go to single-user mode, the Plymouth splashscreen appears briefly, but then a black screen appears with no text (there should be a root console there).
The root console is there however, but invisible, because typing "telinit 2" blindly and then pressing <Enter> returns the system to the normal mode.

If I disable the splashscreen (by removing the "splash" kernel parameter from the GRUB menu), switching to single-user mode works correctly. So, this is definitely a bug in Plymouth!
I can't reproduce this bug is an VirtualBox VM, however (maybe Plymouth doesn't work correctly there).
I must say that I'm using a laptop with Optimus graphics (using bumblebee). Don't know if that could have anything to do with this bug.

Booting into recovery mode works fine.

Another problem: switching to single-user mode kills all the consoles
(tty1-tty6), but returning to normal mode doesn't restart them (lightdm
is restarted correctly). I think this could be a very big problem on a
server.

(I copy-pasted this comment from a similar bug report.)

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to plymouth in Ubuntu.
https://bugs.launchpad.net/bugs/705150

Title:
  Hang trying to enter single-user mode (runlevel 1)

Status in plymouth package in Ubuntu:
  Confirmed

Bug description:
  Binary package hint: upstart

  "telinit 1" causes a hang.  The root shell prompt never appears.  The
  screen is left showing the boot/shutdown splash.

  To reproduce:
  1. Log into a Gnome Classic (no acceleration) session.
      Make sure root has a valid password (run 'sudo passwd root')
  2. Ctl-Alt-F1 to switch to a VT (in VirtualBox, press HostKey+F1)
  3. In the VT, log in as root
  4. telinit 1

  Results:
  The purple "Ubuntu" boot/shutdown splash screen appears, the dots advance for a while, then stop with all dots white.
  Nothing else happens.

  I suspect that the upstart scripts are forgetting to remove the
  shutdown spash screen, and so I can't see the console prompt (just a
  guess).

  NOTE: I'm running in a VirtualBox VM.    I need to enter single-user
  mode to remount the root fs read-only, to prepare to run "zerofree"
  (which zeroes unused blocks, allowing the VM's disk image file to be
  compressed during backups...)

  ProblemType: Bug
  DistroRelease: Ubuntu 11.04
  Package: upstart 0.6.7-4
  ProcVersionSignature: Ubuntu 2.6.37-12.26-generic 2.6.37
  Uname: Linux 2.6.37-12-generic x86_64
  Architecture: amd64
  Date: Wed Jan 19 13:49:50 2011
  InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha amd64 (20101202)
  ProcEnviron:
   LANGUAGE=en_US.UTF-8:en
   LANG=en_US.UTF-8
   LC_MESSAGES=en_AG.utf8
   SHELL=/bin/bash
  SourcePackage: upstart

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/plymouth/+bug/705150/+subscriptions