This happens sometimes on my machine: Ubuntu 12.04 64bit Intel SSD 335 Nvidia GTS 650 with NVIDIA drivers. lightdm version 1.2.3-0ubuntu2.3
Tracked it to a race issue - if NVRM module is loaded before lightdm starts, all is OK. (see logs in Post Scriptum) My current configuration in /etc/init/lightdm.conf: start on ((filesystem and runlevel [!06] and started dbus and plymouth-ready) or runlevel PREVLEVEL=S) Post Scriptum: Logs clearly showing that when lightdm is started before the NVRM module is loaded, and dies a horrible death: Sep 13 14:20:07 Pendragon kernel: [ 5.944960] ADDRCONF(NETDEV_UP): wlan0: link is not ready Sep 13 14:20:07 Pendragon kernel: [ 6.099801] init: lightdm main process (1127) terminated with status 1 Sep 13 14:20:07 Pendragon kernel: [ 6.509805] HDMI status: Codec=0 Pin=5 Presence_Detect=0 ELD_Valid=0 Sep 13 14:20:07 Pendragon kernel: [ 6.533772] HDMI status: Codec=1 Pin=5 Presence_Detect=0 ELD_Valid=0 Sep 13 14:20:07 Pendragon kernel: [ 6.557710] HDMI status: Codec=2 Pin=5 Presence_Detect=0 ELD_Valid=0 Sep 13 14:20:08 Pendragon kernel: [ 6.581717] HDMI status: Codec=3 Pin=5 Presence_Detect=0 ELD_Valid=0 Sep 13 14:20:08 Pendragon kernel: [ 6.581814] input: HDA NVidia HDMI/DP,pcm=9 as /devices/pci0000:00/0000:00:03.0/0000:01:00.1/sound/card1/input10 Sep 13 14:20:08 Pendragon kernel: [ 6.581890] input: HDA NVidia HDMI/DP,pcm=8 as /devices/pci0000:00/0000:00:03.0/0000:01:00.1/sound/card1/input11 Sep 13 14:20:08 Pendragon kernel: [ 6.581954] input: HDA NVidia HDMI/DP,pcm=7 as /devices/pci0000:00/0000:00:03.0/0000:01:00.1/sound/card1/input12 Sep 13 14:20:08 Pendragon kernel: [ 6.582180] input: HDA NVidia HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:03.0/0000:01:00.1/sound/card1/input13 Sep 13 14:20:08 Pendragon kernel: [ 6.583236] nvidia 0000:01:00.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16 Sep 13 14:20:08 Pendragon kernel: [ 6.583243] nvidia 0000:01:00.0: setting latency timer to 64 Sep 13 14:20:08 Pendragon kernel: [ 6.583247] vgaarb: device changed decodes: PCI:0000:01:00.0,olddecodes=io+mem,decodes=none:owns=io+mem Sep 13 14:20:08 Pendragon kernel: [ 6.583341] NVRM: loading NVIDIA UNIX x86_64 Kernel Module 319.32 Wed Jun 19 15:51:20 PDT 2013 Sep 13 14:20:08 Pendragon kernel: [ 6.794290] init: udev-fallback-graphics main process (1380) terminated with status 1 Sep 13 14:20:08 Pendragon kernel: [ 6.951100] init: plymouth-stop pre-start process (1400) terminated with status 1 Sep 13 14:20:08 Pendragon kernel: [ 7.533643] cfg80211: Found new beacon on frequency: 2472 MHz (Ch 13) on phy0 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/969489 Title: lightdm tries (and fails) to start too early? Status in Upstart: New Status in “lightdm” package in Ubuntu: Confirmed Bug description: Sometimes lightdm comes up fine. Other times it appears to fail. x-0.log shows it tried to load 'nv' (rather than 'nvidia' which is what actually exists). When I then log into console and 'start lightdm', it comes up fine (on :1). I've not had it come up ok today, so I don't know if, when it comes up fine, it starts on :0. No idea if the lightdm.conf needs a change to 'start on'clause, or if this is just a case of a bad shipped config file (for module 'nv'). ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: lightdm 1.1.9-0ubuntu1 ProcVersionSignature: Ubuntu 3.2.0-20.33-generic 3.2.12 Uname: Linux 3.2.0-20-generic x86_64 NonfreeKernelModules: nvidia ApportVersion: 2.0-0ubuntu1 Architecture: amd64 Date: Fri Mar 30 13:40:27 2012 InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120323) ProcEnviron: TERM=xterm PATH=(custom, user) LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: lightdm UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/upstart/+bug/969489/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp