systemd will not start lightdm correctly

[Joolz]

On a complete clean install of 15.04 32bits on an Asus eee which used to work allright for a few days, I now have an issue. The system will not start the GUI, I land in emergency mode which says "Error getting authority: Error initializing authority: Could not connect: No such file or directory (g-io-error-quark, 1)" and suggests to ^D to attempt to boot into default mode

When I do this, GUI login is possible and the system works fine. However, shutting down brings me back to the emergency shell and I have to power down with the hardware button.

I tried `sudo systemctl enable lightdm` but that gives me:

Synchronizing state for lightdm.service with sysvinit using update-rc.d...
Executing /usr/sbin/update-rc.d lightdm defaults
Executing /usr/sbin/update-rc.d lightdm enable
The unit files have no [Install] section. They are not meant to be enabled
using systemctl.
Possible reasons for having this kind of units are:
1) A unit may be statically enabled by being symlinked from another unit's
   .wants/ or .requires/ directory.
2) A unit's purpose may be to act as a helper for some other unit which has
   a requirement dependency on it.
3) A unit may be started when needed via activation (socket, path, timer,
   D-Bus, udev, scripted systemctl call, ...).

So I tried `sudo dpkg-reconfigure lightdm` (as suggested by https://askubuntu.com/questions/614198/starting-version-219-bug-after-the-15-04-update and https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=764607) which runs without errors but doesn't change the result of `sudo systemctl enable lightdm`

[Luís (luiss351)]

I have this problem after upgrading to Lubuntu 15.04 32bit.

"The system will not start the GUI, I land in emergency mode which says "Error getting authority: Error initializing authority: Could not connect: No such file or directory (g-io-error-quark, 1)" and suggests to ^D to attempt to boot into default mode."

When I press ^D it just says the same thing again. After pressing it a few times, it starts to ignore keyboard input (numlock led changes, but caps lock does not).

"sudo systemctl enable lightdm" gives the same output, but with some lines of "Error getting authority: Error initializing authority: Could not connect: No such file or directory (g-io-error-quark, 1)" mixed in and also does not solve the problem.

However, if I choose to boot with upstart instead, under advaced boot options, everthing (including lighdm) works fine.

[Luís (luiss351)]

I read the startup log using "journalctl -xe" (attached, in case anyone wants to check it out).
It seemed D-Bus, among other things, failed to start with result 'dependency'.
Turns out /var/run was not being (properly?) mounted.
systemd[1]: var-run.mount failed to run 'mount' task (...)

I found this solution, which is exactly for my case (after upgrade):
http://c0rp.kz/ubuntu-boot-problem-after-upgrade-14-10-15-04/

All I had to do was comment the following line from /etc/fstab and it solved the problem:
/var/run tmpfs size=3M,noatime 0 0

It was likely me who added that to fstab in the past, and I realize now that had the same problem on my laptop, except instead of trying to fix it and understand why, I reinstalled the whole system in a rush.

Joolz, try to check the startup log ("journalctl -xe" ) to see what's going on. I don't think this will be the cause, since it's a fresh install, but you may find some info there.

Hope this helps anyone having the same problem.
Cheers.