Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

How can I boot into recovery mode if it hangs booting into single user mode?

I am trying to boot into "recovery mode" or any single user mode, but upstart is trying to start modem-manager no matter what. It says "modem-manager could not connect to system bus" and sits there retrying, forever.

Can I boot into single user mode and tell upstart to NOT try starting the modem?

Can I boot single user and tell upstart to start a shell after drives are mounted? Thanks for any help in advance...

UPDATE: I was able to use the grub init=/bin/bash trick to get a command prompt on booting. From there I was able to apt-get purge modemmanager. But I still get an error about can't connect to system bus and a hang. Is there a way to put upstart into extra verbose mode so I can see what is causing the hang?

share|improve this question
When you boot, remove the "quiet" from the boot options. When you get a shell, check the logs. If it will not boot at all, we can investigate from a live CD. – bodhi.zazen Dec 21 '11 at 20:14
up vote 2 down vote accepted

After a lot of Googling the different terms, I found a post that may solve your problem also.

For me that was a bug for Ubuntu 11.10. Take a look at this post for solution. And to repeat the solution here:

  1. Hit Ctrl+Alt+F1 at the blank screen to get you to a non-X terminal (tty1)
  2. Login in with your username and password
  3. Change to root with: sudo -i and enter your password
  4. mkdir -p /run /run/lock
  5. rm -rf /var/run /var/lock
  6. ln -s /run /var
  7. ln -s /run/lock /var
  8. Reboot
share|improve this answer
TY! I had no idea /var/run and moved to /run and is symlinked and same goes for /var/lock and both are tmpfs. I googled a ton and never saw this blog post nor any detail that they are tmpfs. – Jay _silly_evarlast_ Wren Jan 6 '12 at 22:20

"Could not connect to the system bus" means dbus. Without dbus, you probably can't boot. I think you need to figure out why dbus isn't starting.

Are you using a standard kernel?

share|improve this answer
yes, you are right, no dbus. yes standard kernel. when I init=/bin/sh and try service start, it says dbus is already running. I guess because /var/run/dbus/pid is there because of unclean shutdown. – Jay _silly_evarlast_ Wren Jan 6 '12 at 22:19

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.