Jtdcftul

Reposting the question from: https://unix.stackexchange.com/q/314129/193223

I recently upgraded from Ubuntu 14.04 to 16.04 after which the display manager stopped working.

Assuming it's due to the init systems, I tried to switch back to upstart by following the instructions given on this page:

https://wiki.ubuntu.com/SystemdForUpstartUsers

It didn't work.

newton@gravity:~$ sudo systemctl status lightdm

● lightdm.service - Light Display Manager

   Loaded: loaded (/lib/systemd/system/lightdm.service; enabled; vendor preset: enabled)

  Drop-In: /lib/systemd/system/display-manager.service.d

           └─xdiagnose.conf

   Active: inactive (dead) (Result: exit-code) since Mon 2016-10-03 19:04:26 EDT; 13min ago

     Docs: man:lightdm(1)

  Process: 3533 ExecStart=/usr/sbin/lightdm (code=exited, status=1/FAILURE)

  Process: 3528 ExecStartPre=/bin/sh -c [ "$(basename $(cat /etc/X11/default-display-manager 2>/dev/null))" = "lightdm" ] (code=exited, status=0/SUCCESS)

 Main PID: 3533 (code=exited, status=1/FAILURE)



Oct 03 19:04:26 newton systemd[1]: lightdm.service: Failed with result 'exit-code'.

Oct 03 19:04:26 newton systemd[1]: lightdm.service: Service hold-off time over, scheduling restart.

Oct 03 19:04:26 newton systemd[1]: Stopped Light Display Manager.

Oct 03 19:04:26 newton systemd[1]: lightdm.service: Start request repeated too quickly.

Oct 03 19:04:26 newton systemd[1]: Failed to start Light Display Manager.

Oct 03 19:09:02 newton systemd[1]: Stopped Light Display Manager.

journalctl shows issues with PAM kwallet.

$ sudo journalctl -e -u lightdm

...

systemd[1]: Starting Light Display Manager...

systemd[1]: Started Light Display Manager.

lightdm[26952]: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory

lightdm[26952]: PAM adding faulty module: pam_kwallet.so

lightdm[26952]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory

lightdm[26952]: PAM adding faulty module: pam_kwallet5.so

lightdm[26952]: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)

systemd[1]: lightdm.service: Main process exited, code=exited, status=1/FAILURE

systemd[1]: lightdm.service: Unit entered failed state.

systemd[1]: lightdm.service: Triggering OnFailure= dependencies.

systemd[1]: lightdm.service: Failed with result 'exit-code'.



...

Here's the content of /var/log/lightdm/lightdm.log;

[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log

[+0.00s] DEBUG: Starting Light Display Manager 1.18.2, UID=0 PID=26937

[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d

[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-disable-log-backup.conf

[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-greeter-wrapper.conf

[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-guest-wrapper.conf

[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf

[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf

[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-xserver-command.conf

[+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d

[+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d

[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf

[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager

[+0.00s] DEBUG: Registered seat module xlocal

[+0.00s] DEBUG: Registered seat module xremote

[+0.00s] DEBUG: Registered seat module unity

[+0.00s] DEBUG: Monitoring logind for seats

[+0.00s] DEBUG: New seat added from logind: seat0

[+0.00s] DEBUG: Seat seat0: Loading properties from config section Seat:*

[+0.00s] DEBUG: Seat seat0: Starting

[+0.00s] DEBUG: Seat seat0: Creating greeter session

[+0.00s] DEBUG: Seat seat0: Creating display server of type x

[+0.01s] DEBUG: Using VT 7

[+0.01s] DEBUG: Seat seat0: Starting local X display on VT 7

[+0.01s] DEBUG: DisplayServer x-0: Logging to /var/log/lightdm/x-0.log

[+0.01s] DEBUG: DisplayServer x-0: Writing X server authority to /var/run/lightdm/root/:0

[+0.01s] DEBUG: DisplayServer x-0: Launching X Server

[+0.01s] DEBUG: Launching process 26944: /usr/bin/X -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch

[+0.01s] DEBUG: DisplayServer x-0: Waiting for ready signal from X server :0

[+0.01s] DEBUG: Acquired bus name org.freedesktop.DisplayManager

[+0.01s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0

[+0.01s] DEBUG: Loading users from org.freedesktop.Accounts

[+0.01s] DEBUG: User /org/freedesktop/Accounts/User1000 added

[+0.01s] DEBUG: User /org/freedesktop/Accounts/User1007 added

[+0.01s] DEBUG: User /org/freedesktop/Accounts/User1009 added

[+0.01s] DEBUG: User /org/freedesktop/Accounts/User1006 added

[+0.01s] DEBUG: User /org/freedesktop/Accounts/User1005 added

[+0.01s] DEBUG: User /org/freedesktop/Accounts/User1002 added

[+0.02s] DEBUG: User /org/freedesktop/Accounts/User1011 added

[+0.02s] DEBUG: User /org/freedesktop/Accounts/User1008 added

[+0.02s] DEBUG: User /org/freedesktop/Accounts/User1003 added

[+0.02s] DEBUG: User /org/freedesktop/Accounts/User1001 added

[+0.02s] DEBUG: User /org/freedesktop/Accounts/User1004 added

[+0.02s] DEBUG: User /org/freedesktop/Accounts/User1010 added

[+0.23s] DEBUG: Got signal 10 from process 26944

[+0.23s] DEBUG: DisplayServer x-0: Got signal from X server :0

[+0.23s] DEBUG: DisplayServer x-0: Connecting to XServer :0

[+0.23s] DEBUG: Seat seat0: Display server ready, starting session authentication

[+0.23s] DEBUG: Session pid=26952: Started with service 'lightdm-greeter', username 'lightdm'

[+0.25s] DEBUG: Session pid=26952: Authentication complete with return value 0: Success

[+0.25s] DEBUG: Seat seat0: Session authenticated, running command

[+0.25s] DEBUG: Session pid=26952: Running command /usr/lib/lightdm/lightdm-greeter-session /usr/sbin/unity-greeter

[+0.25s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm

[+0.25s] DEBUG: Session pid=26952: Logging to /var/log/lightdm/seat0-greeter.log

[+0.27s] DEBUG: Activating VT 7

[+0.27s] DEBUG: Activating login1 session c17

[+0.27s] DEBUG: Seat seat0 changes active session to c17

[+0.27s] DEBUG: Session c17 is already active

[+0.37s] DEBUG: Greeter closed communication channel

[+0.37s] DEBUG: Session pid=26952: Exited with return value 0

[+0.37s] DEBUG: Seat seat0: Session stopped

[+0.37s] DEBUG: Seat seat0: Stopping; failed to start a greeter

[+0.37s] DEBUG: Seat seat0: Stopping

[+0.37s] DEBUG: Seat seat0: Stopping display server

[+0.37s] DEBUG: Sending signal 15 to process 26944

[+0.50s] DEBUG: Process 26944 exited with return value 0

[+0.50s] DEBUG: DisplayServer x-0: X server stopped

[+0.50s] DEBUG: Releasing VT 7

[+0.50s] DEBUG: DisplayServer x-0: Removing X server authority /var/run/lightdm/root/:0

[+0.50s] DEBUG: Seat seat0: Display server stopped

[+0.50s] DEBUG: Seat seat0: Stopped

[+0.50s] DEBUG: Required seat has stopped

[+0.50s] DEBUG: Stopping display manager

[+0.50s] DEBUG: Display manager stopped

[+0.50s] DEBUG: Stopping daemon

[+0.50s] DEBUG: Exiting with return value 1



Any other debugging tips that I need to try?

It happened to me also try using gdm3 instead if you have it. If you have gdm3 then go to the terminal and type "sudo apt remove lightdm" and after that " sudo apt-get install lightdm".