It seems though it can be guessed more or less what can cause problems (ie thinkpad + lightdm + systemd) the exact details are not the same, and some other conditions can/do count as well. Also the "not always" factor sometimes, kinda odd.
However, as bug 1340964 if often referenced for me, and it is about some kind of VT activation problem, can it be because some race condition on using VTs or such? Since systemd may do deeper parallelism on the boot process than upstart (I am not sure just guessing) or at least it did it not the very same way, it can explain why it works with upstart but not with systemd. But really, I am just guessing, and trying to give hints, as release data for vivid is coming and this bug still exists rendering ubuntu totally unusable for normal users on some hardware like some thinkpad notebooks which are not so rare, I think. -- 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/1434396 Title: Xserver does not start on boot (low-graphics mode) Status in Light Display Manager: Confirmed Status in lightdm package in Ubuntu: Triaged Bug description: After upgrading to (32bit) vivid I hadn't got any problem, but since a day (daily upgraded) booting results in a dialog saying low graphics mode and a dialog window about this. Choosing running in default mode causes to boot splash to be shown forever. if I choose exit to console, log in then service stop then start for lightdm, it works then though. Maybe is not Xserver bug, but the new init system (systemd) race condition of starting things, or such? ProblemType: Bug DistroRelease: Ubuntu 15.04 Package: xserver-xorg 1:7.7+7ubuntu4 ProcVersionSignature: Ubuntu 3.19.0-9.9-generic 3.19.1 Uname: Linux 3.19.0-9-generic i686 .tmp.unity.support.test.0: ApportVersion: 2.16.2-0ubuntu3 Architecture: i386 CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins' CompositorRunning: compiz CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0' CompositorUnredirectFSW: true CurrentDesktop: Unity Date: Fri Mar 20 07:35:37 2015 DistUpgraded: 2014-10-24 18:45:04,038 DEBUG enabling apt cron job DistroCodename: vivid DistroVariant: ubuntu DkmsStatus: virtualbox, 4.3.26, 3.19.0-9-generic, i686: installed ExtraDebuggingInterest: Yes GraphicsCard: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0116] (rev 09) (prog-if 00 [VGA controller]) Subsystem: Lenovo Device [17aa:21dd] InstallationDate: Installed on 2012-03-03 (1111 days ago) InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1) MachineType: LENOVO 5016NW6 ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.19.0-9-generic root=UUID=8df578aa-47e3-483f-b694-bf7effd24b7d ro i915.semaphores=0 quiet splash vt.handoff=7 SourcePackage: xorg UpgradeStatus: Upgraded to vivid on 2014-10-24 (146 days ago) dmi.bios.date: 11/04/2011 dmi.bios.vendor: LENOVO dmi.bios.version: 8GET38WW (1.15 ) dmi.board.name: 5016NW6 dmi.board.vendor: LENOVO dmi.board.version: Not Available dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Not Available dmi.modalias: dmi:bvnLENOVO:bvr8GET38WW(1.15):bd11/04/2011:svnLENOVO:pn5016NW6:pvrThinkPadL520:rvnLENOVO:rn5016NW6:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable: dmi.product.name: 5016NW6 dmi.product.version: ThinkPad L520 dmi.sys.vendor: LENOVO version.compiz: compiz 1:0.9.12.1+15.04.20150303-0ubuntu1 version.libdrm2: libdrm2 2.4.59-0ubuntu1 version.libgl1-mesa-dri: libgl1-mesa-dri 10.5.0-0ubuntu1 version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A version.libgl1-mesa-glx: libgl1-mesa-glx 10.5.0-0ubuntu1 version.xserver-xorg-core: xserver-xorg-core 2:1.17.1-0ubuntu3 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.0-1ubuntu2 version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.5.0-1ubuntu2 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917-1~exp1ubuntu2build1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu2build1 xserver.bootTime: Fri Mar 20 07:25:51 2015 xserver.configfile: default xserver.errors: xserver.logfile: /var/log/Xorg.0.log xserver.outputs: product id 9196 vendor AUO xserver.version: 2:1.17.1-0ubuntu3 To manage notifications about this bug go to: https://bugs.launchpad.net/lightdm/+bug/1434396/+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