[upstart] console access of the server is lost when trying to change runlevel 3 from runlevel 1

[bugproxy]

Problem Description
============================
console access is lost if #init 3 ; is run from #init 1 ;

---uname output---
 4.2.0-30-generic #35~14.04.1-Ubuntu SMP Fri Feb 19 15:23:48 UTC 2016 ppc64le ppc64le ppc64le GNU/Linux

Machine Type = 8247-22L

Steps to Reproduce
====================================
login to console of ubuntu 14.04.4 system (either on bare-metal or PowerVM based lpar ) , use ipmitool console for bare-metal, use mkvterm console from hmc for PowerVM based lpar.
#runlevel ; to check the current default run level
#init 1;
#init 3; or ; #exit

Console access is lost [hung] cannot regain the console, only solution is reboot of the server.

=========console logs=======
root@ltcbrazos2-lp18:~# init 1
root@ltcbrazos2-lp18:~# Skip stopping firewall: ufw (not enabled)
wait-for-state stop/waiting
 * Stopping rsync daemon rsync [ OK ]
                                                                         [ OK ]
 * Killing all remaining processes... [fail]
 * Will now switch to single-user mode
Give root password for maintenance
(or type Control-D to continue):
root@ltcbrazos2-lp18:~#
root@ltcbrazos2-lp18:~#
root@ltcbrazos2-lp18:~# runlevel
1 S
root@ltcbrazos2-lp18:~# init 3
root@ltcbrazos2-lp18:~# exit
 * Restoring resolver state... [ OK ]

===========================
Console is hung indefinitely, no login prompt is offered
===========================
Please note the system successfully goes to #init 3 ;
network comes back, SSH works, but cannot access the system via any console.

Userspace rpm: upstart

== Comment: #2 - NAVEED A. UPPINANGADY SALIH <email address hidden> - 2016-02-26 07:28:47 ==
(In reply to comment #1)
> Hi Naveed,
>
> Can you please check for 'who -r' once you switch to runlevel 3 ?
> What is the intention of the exit command here ? Is it for you to terminate
> your session ? Is the terminal available for you to execute other commands
> as well or does it hang at that stage as well?
>
> Thank you.

you can access the system via terminal using ssh even though console is not accessible
==========
root@ltcbrazos2-lp18:~# who -r
         run-level 3 2016-02-26 07:14 last=S
==========

I think "exit" or "init 3" either of the command does same from runlevel 1 ?
Correct me if I am wrong.

from ssh session if "init 6" or "init 1" is issued again, we are able to access the console again.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1557990/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Steve Langasek (vorlon)]

I can confirm that the code for the upstart jobs in 14.04 behaves as you describe. However, this seems to be the first time since 14.04 released, two years ago, that someone has noticed this behavior and considered it to warrant a bug report.

While switching to runlevel 1 and back *should* restore the consoles, this is not at all a common maintenance operation. Ubuntu users will normally reboot instead of switching between runlevels in this manner. Added to this that you have marked this bug as 'medium' severity, thus meaning that it does not rise to the level of a stable release update; and the fact that fixing this in 14.04 would be non-trivial; I am declining this bug as 'wontfix'.

For Ubuntu 16.04, consoles are implemented differently via systemd. If you see any bugs in the handling of runlevel switches with systemd, it would be useful to know this so that we might fix them before 16.04 GA.