Ubuntu 16 doesn't boot graphically and startx doesn't work

Question

Ubuntu used to work almost fine the last two weeks, I restarted it to play a game under windows, I restarted it again to boot Ubuntu again and now if I boot normally, it gets stuck in the boot screen. The dots under ubuntu won’t move.

• if I press ALT+F2 it says

  A start job is running for Hold until boot process finishes up (xxmin xxs / no limit)
  

• if I try to reinstall Ubuntu with a thumbdrive the only option is to erase everything, I wanted to try to salvage the installation I’ve been using so far.

Through recovery mode:

• network says

  Trying to start NetworkManager...  
  unknow username “geoclue” in message bus configuration file
  grep: /etc/resolv.conf: No Such file or directory   
  

  and then repeats that last line 16 times

• if I hit resume, the screen blinks and keypresses are not always detected but I can login through the command line

  • startx returns this confusing screen

  • I’ve tried (I have an hd6850)

    sudo apt-get purge "fglrx.*"
    sudo rm /etc/X11/xorg.conf
    sudo apt-get install --reinstall xserver-xorg-core libgl1-mesa-glx:i386 libgl1-mesa-dri:i386 libgl1-mesa-glx:amd64 libgl1-mesa-dri:amd64
    sudo dpkg-reconfigure xserver-xorg
    sudo reboot
    

and now I cannot even see ubuntu and the dots (but everything else is unchanged)

How could I resolve this quite big issue?

Solution

a user in other more active forum suggested me this, I'm adding it to give more insight:

startx will not work in 16.04 which uses systemd, not upstart, but you may get somewhere by using command Code:

sudo service lightdm start

However, that does not really help us to figure out what has happened and why you no longer boot to a desktop.

doing that returned

Job for lightdm.service failed because the control process exited with error code. See "systemctl status lightdm.service" and "journalctl -xe" for details.  

---

then I've been told

Run those two command shown in a terminal and see what output you get. Code:

systemctl status lightdm.service
journalctl -xe

the first one returned

lightdm.service - Light Display Manager    Loaded: loaded (/lib/systemd/system/lightdm.service; static; vendor preset: enabled       
Active: inactive (dead)         
Docs: man:lightdm(1)

the second one returned 3707 lines, the ones with colord-sane are red and return the same error, example:

colord-sane[12163]: io/hpmud/pp.c 627: unable to read device-id ret=-1

Comments

[Organic Marble]

Are you sure the only reinstall option is erase everything? Couldn't you do a Something Else and not format /?