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zexar

Member

Registered: 2009-05-15

Posts: 23

"Failed to open private bus connection" when lightdm starting

Hello!
When I try to start gnome or cinnamon through lightdm I've got black screen in case of cinnamon or non informative dialog window in case of gnome. All of this after login.
I found this strings in logs

Nov 05 15:48:50 aaaa lightdm[160]: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)
Nov 05 15:48:50 aaaa systemd[1]: Starting user-620.slice.
Nov 05 15:48:50 aaaa systemd[1]: Created slice user-620.slice.
Nov 05 15:48:50 aaaa systemd[1]: Starting User Manager for 620...
Nov 05 15:48:50 aaaa systemd-logind[145]: New session c1 of user lightdm.
Nov 05 15:48:50 aaaa systemd-logind[145]: Linked /tmp/.X11-unix/X0 to /run/user/620/X11-display.
Nov 05 15:48:50 aaaa systemd[1]: Starting Session c1 of user lightdm.
Nov 05 15:48:50 aaaa systemd[1]: Started Session c1 of user lightdm.
Nov 05 15:48:50 aaaa systemd[173]: pam_unix(systemd-user:session): session opened for user lightdm by (uid=0)
Nov 05 15:48:50 aaaa systemd[173]: Failed to open private bus connection: Failed to connect to socket /run/user/620/dbus/user_bus_socket: No such file or directory
Nov 05 15:48:50 aaaa systemd[173]: Mounted /sys/kernel/config.
Nov 05 15:48:50 aaaa systemd[173]: Stopped target Sound Card.
Nov 05 15:48:50 aaaa systemd[173]: Starting Default.
Nov 05 15:48:50 aaaa systemd[173]: Reached target Default.
Nov 05 15:48:50 aaaa systemd[173]: Startup finished in 373ms.
Nov 05 15:48:50 aaaa systemd[1]: Started User Manager for 620.

Is it correct? Why "session opened" but "Failed to open private bus connection"? What should I check to figure out the problem?

Thank you.

zexar

Member

Registered: 2009-05-15

Posts: 23

Re: "Failed to open private bus connection" when lightdm starting

I've examined log files and find out next

1. Every time I logged in (or, maybe even during every boot) there are message about private bus coonection appear. But it consist uid=0 not 620. It looks like /run/user/0/dbus/user_bus_socket. But seems to everything works fine.

2. Path '/run/user/620/dbus/user_bus_socket' exist but this is a directory. It contain soket file deeper itself. Full path look like '/run/user/620/dbus/user_bus_socket/systemd/=private'.

3. Similar path for user 620 haven't created.

4. systemd service description user@.service export this path in variable DBUS_SESSION_BUS_ADDRESS. It looks like '/run/user/%i/dbus/user_bus_socket. And I don't know where ending of path appear from.

5. I found reference on Arch wiki about file '/etc/systemd/system/user@.service.d/environment.conf'. But I don't know is it really need, why it contain path XDG_RUNTIME_DIR differ from DBUS_SESSION_BUS_ADDRESS and I didn't find any reference about somthing like directory user@.service.d in systemd documentation.

What do you thing about all of this? Any ideas?
I'm not sure that all of this helps to start lightdm but it's became interesting.

Sorry for bad English.

zexar

Member

Registered: 2009-05-15

Posts: 23

Re: "Failed to open private bus connection" when lightdm starting

I have solved gnome startup trouble. Solution was simple - I just fogot to add launch of VBoxClient-all to my .xinitrc file. System have no hardware graphics acceleration because of this.
But I have no idea what to do about systemd.