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compul

Member

Registered: 2016-12-08

Posts: 23

Systemd won't start lightdm, but manually works fine

Hey,

when I boot or run

# systemctl start lightdm

, lightdm won't start. This is the lightdm.log:

[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.30.0, UID=0 PID=9165
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+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: Registered seat module local
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.00s] DEBUG: _g_io_module_get_default: Found default implementation local (GLocalVfs) for ‘gio-vfs’
[+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
[+0.00s] DEBUG: posix_spawn avoided (fd close requested) 
[+0.00s] DEBUG: Could not run plymouth --ping: Failed to execute child process “plymouth” (No such file or directory)
[+0.00s] DEBUG: Using VT 7
[+0.00s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.00s] DEBUG: XServer 0: Logging to /var/log/lightdm/x-0.log
[+0.00s] DEBUG: XServer 0: Writing X server authority to /run/lightdm/root/:0
[+0.00s] DEBUG: XServer 0: Launching X Server
[+0.00s] DEBUG: Launching process 9171: /usr/bin/X :0 -seat seat0 -auth /run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.00s] DEBUG: XServer 0: Waiting for ready signal from X server :0
[+0.00s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.00s] 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: posix_spawn avoided (automatic reaping requested) (fd close requested) 
[+0.04s] DEBUG: Seat seat0 changes active session to 
[+0.51s] DEBUG: Got signal 10 from process 9171
[+0.51s] DEBUG: XServer 0: Got signal from X server :0
[+0.51s] DEBUG: XServer 0: Connecting to XServer :0
[+0.52s] DEBUG: posix_spawn avoided (fd close requested) (child_setup specified) 
[+0.52s] DEBUG: Seat seat0: Display server ready, starting session authentication
[+0.52s] DEBUG: Session pid=9181: Started with service 'lightdm-greeter', username 'lightdm'
[+0.53s] DEBUG: Session pid=9181: Authentication complete with return value 0: Success
[+0.53s] DEBUG: Seat seat0: Session authenticated, running command
[+0.53s] DEBUG: Session pid=9181: Running command /usr/bin/lightdm-mini-greeter
[+0.53s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm
[+0.53s] DEBUG: Session pid=9181: Logging to /var/log/lightdm/seat0-greeter.log
[+0.54s] DEBUG: Activating VT 7
[+0.54s] DEBUG: Activating login1 session c30
[+0.54s] DEBUG: Seat seat0 changes active session to c30
[+0.54s] DEBUG: Session c30 is already active
[+0.64s] DEBUG: Greeter connected version=1.30.0 api=1 resettable=false
[+0.64s] DEBUG: Greeter start authentication for XXX
[+0.64s] DEBUG: Session pid=9194: Started with service 'lightdm', username 'XXX'
[+0.65s] DEBUG: Session pid=9194: Got 1 message(s) from PAM
[+0.65s] DEBUG: Prompt greeter with 1 message(s)
[+1.02s] DEBUG: Greeter closed communication channel
[+1.02s] DEBUG: Session pid=9181: Exited with return value 1
[+1.02s] DEBUG: Seat seat0: Session stopped
[+1.02s] DEBUG: Seat seat0: Stopping; failed to start a greeter
[+1.02s] DEBUG: Seat seat0: Stopping
[+1.02s] DEBUG: Seat seat0: Stopping display server
[+1.02s] DEBUG: Sending signal 15 to process 9171
[+1.02s] DEBUG: Seat seat0: Stopping session
[+1.02s] DEBUG: Session pid=9194: Sending SIGTERM
[+1.02s] DEBUG: Session pid=9194: Terminated with signal 15
[+1.02s] DEBUG: Session: Failed during authentication
[+1.02s] DEBUG: Seat seat0: Session stopped
[+1.03s] DEBUG: Seat seat0 changes active session to 
[+1.28s] DEBUG: Process 9171 exited with return value 0
[+1.28s] DEBUG: XServer 0: X server stopped
[+1.28s] DEBUG: Releasing VT 7
[+1.28s] DEBUG: XServer 0: Removing X server authority /run/lightdm/root/:0
[+1.28s] DEBUG: Seat seat0: Display server stopped
[+1.28s] DEBUG: Seat seat0: Stopped
[+1.28s] DEBUG: Required seat has stopped
[+1.28s] DEBUG: Stopping display manager
[+1.28s] DEBUG: Display manager stopped
[+1.28s] DEBUG: Stopping daemon
[+1.29s] DEBUG: Exiting with return value 1

In particular it mentions "[+1.02s] DEBUG: Seat seat0: Stopping; failed to start a greeter". This is the log when running

sudo lightdm

[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.30.0, UID=0 PID=9253
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+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: Registered seat module local
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.00s] DEBUG: _g_io_module_get_default: Found default implementation local (GLocalVfs) for ‘gio-vfs’
[+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
[+0.00s] DEBUG: posix_spawn avoided (fd close requested) 
[+0.00s] DEBUG: Could not run plymouth --ping: Failed to execute child process “plymouth” (No such file or directory)
[+0.00s] DEBUG: Using VT 7
[+0.00s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.00s] DEBUG: XServer 0: Logging to /var/log/lightdm/x-0.log
[+0.00s] DEBUG: XServer 0: Writing X server authority to /run/lightdm/root/:0
[+0.00s] DEBUG: XServer 0: Launching X Server
[+0.00s] DEBUG: Launching process 9259: /usr/bin/X :0 -seat seat0 -auth /run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.00s] DEBUG: XServer 0: Waiting for ready signal from X server :0
[+0.00s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.00s] 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: posix_spawn avoided (automatic reaping requested) (fd close requested) 
[+0.05s] DEBUG: Seat seat0 changes active session to 
[+0.55s] DEBUG: Got signal 10 from process 9259
[+0.55s] DEBUG: XServer 0: Got signal from X server :0
[+0.55s] DEBUG: XServer 0: Connecting to XServer :0
[+0.55s] DEBUG: posix_spawn avoided (fd close requested) (child_setup specified) 
[+0.55s] DEBUG: Seat seat0: Display server ready, starting session authentication
[+0.55s] DEBUG: Session pid=9269: Started with service 'lightdm-greeter', username 'lightdm'
[+0.56s] DEBUG: Session pid=9269: Authentication complete with return value 0: Success
[+0.56s] DEBUG: Seat seat0: Session authenticated, running command
[+0.56s] DEBUG: Session pid=9269: Running command /usr/bin/lightdm-mini-greeter
[+0.56s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm
[+0.56s] DEBUG: Session pid=9269: Logging to /var/log/lightdm/seat0-greeter.log
[+0.57s] DEBUG: Activating VT 7
[+0.67s] DEBUG: Greeter connected version=1.30.0 api=1 resettable=false
[+0.67s] DEBUG: Greeter start authentication for XXX
[+0.67s] DEBUG: Session pid=9281: Started with service 'lightdm', username 'XXX'
[+0.68s] DEBUG: Session pid=9281: Got 1 message(s) from PAM
[+0.68s] DEBUG: Prompt greeter with 1 message(s)
[+2.40s] DEBUG: Continue authentication
[+2.42s] DEBUG: Session pid=9281: Authentication complete with return value 0: Success
[+2.42s] DEBUG: Authenticate result for user XXX: Success
[+2.42s] DEBUG: User XXX authorized
[+2.42s] DEBUG: Greeter requests default session
[+2.42s] DEBUG: Seat seat0: Stopping greeter; display server will be re-used for user session
[+2.42s] DEBUG: Session pid=9269: Sending SIGTERM
[+2.43s] DEBUG: Greeter closed communication channel
[+2.43s] DEBUG: Session pid=9269: Exited with return value 1
[+2.43s] DEBUG: Seat seat0: Session stopped
[+2.43s] DEBUG: Seat seat0: Greeter stopped, running session
[+2.43s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+2.43s] DEBUG: posix_spawn avoided (fd close requested) (child_setup specified) 
[+2.43s] DEBUG: Session pid=9281: Running command /etc/lightdm/Xsession i3
[+2.43s] DEBUG: Creating shared data directory /var/lib/lightdm-data/XXX
[+2.43s] DEBUG: Session pid=9281: Logging to .xsession-errors
[+2.44s] DEBUG: Activating VT 7

Also, I don't know whether the following has any relevancy:

$ cat /var/log/Xorg.0.log | grep EE
[  1644.894] (EE) Failed to load module "fbdev" (module does not exist, 0)

Any clue why starting from systemd is different than manually?

Last edited by compul (2020-07-08 04:20:54)

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 77,762

Re: Systemd won't start lightdm, but manually works fine

I don't know whether the following has any relevancy

No. The message is harmless.

[+0.64s] DEBUG: Greeter start authentication for XXX
[+0.64s] DEBUG: Session pid=9194: Started with service 'lightdm', username 'XXX'
[+0.65s] DEBUG: Session pid=9194: Got 1 message(s) from PAM
[+0.65s] DEBUG: Prompt greeter with 1 message(s)

[+1.02s] DEBUG: Greeter closed communication channel

[+0.67s] DEBUG: Greeter start authentication for XXX
[+0.67s] DEBUG: Session pid=9281: Started with service 'lightdm', username 'XXX'
[+0.68s] DEBUG: Session pid=9281: Got 1 message(s) from PAM
[+0.68s] DEBUG: Prompt greeter with 1 message(s)

[+2.40s] DEBUG: Continue authentication
[+2.42s] DEBUG: Session pid=9281: Authentication complete with return value 0: Success
[+2.42s] DEBUG: Authenticate result for user XXX: Success
[+2.42s] DEBUG: User XXX authorized

Are you using some sort of autologin?
The authentication takes almost 2 seconds and in the service case the greeter stops after ~0.5 seconds.

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compul

Member

Registered: 2016-12-08

Posts: 23

Re: Systemd won't start lightdm, but manually works fine

I don't think so. I thought those two seconds were just how long it took me to enter my password?

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 77,762

Re: Systemd won't start lightdm, but manually works fine

lightdm and the greeter start, the greeter terminates after ~0.5 seconds.
a) do you see the greeter flashing up?
b) does it work with eg. the gtk greeter?

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How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

compul

Member

Registered: 2016-12-08

Posts: 23

Re: Systemd won't start lightdm, but manually works fine

a) No, I just see a black screen with a blinking cursor in the top left.
b) going to get back to you regarding other greeters.

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 77,762

Re: Systemd won't start lightdm, but manually works fine

Almost sounds like https://wiki.archlinux.org/index.php/Li … TTY_output but the context is weird.

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How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc