부팅 시 lightdm이 제대로 시작되지 않습니다(터미널에서 실행).

저는 ElementaryOS를 사용하고 있으며 커널을 3.11로 업데이트한 후 부팅 후 검은색 화면이 나타납니다. 명령 프롬프트에 go를 입력 Ctrl + Alt + F1한 다음 do를 입력하면 sudo service lightdm restartlightdm이 올바르게 시작됩니다.

왜 애초에 시작되지 않는 걸까요? 이전에 X 스택과 드라이버에 문제가 있었던 적이 있는데 이것이 문제라면 터미널에서 lightdm을 실행조차 할 수 없을 것 같습니다.

Lightdm.log

[+0.00s] DEBUG: Starting Light Display Manager 1.2.3, UID=0 PID=3650
[+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: Adding default seat
[+0.00s] DEBUG: Starting seat
[+0.00s] DEBUG: Starting new display for greeter
[+0.00s] DEBUG: Starting local X display
[+0.00s] DEBUG: Using VT 7
[+0.00s] DEBUG: Activating VT 7
[+0.01s] DEBUG: Logging to /var/log/lightdm/x-0.log
[+0.01s] DEBUG: Writing X server authority to /var/run/lightdm/root/:0
[+0.01s] DEBUG: Launching X Server
[+0.01s] DEBUG: Launching process 3659: /usr/bin/X :0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.01s] DEBUG: 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
[+1.01s] DEBUG: Got signal 10 from process 3659
[+1.01s] DEBUG: Got signal from X server :0
[+1.01s] DEBUG: Connecting to XServer :0
[+1.01s] DEBUG: Starting greeter
[+1.01s] DEBUG: Started session 3747 with service 'lightdm', username 'lightdm'
[+1.05s] DEBUG: Session 3747 authentication complete with return value 0: Success
[+1.05s] DEBUG: Greeter authorized
[+1.05s] DEBUG: Logging to /var/log/lightdm/x-0-greeter.log
[+1.05s] DEBUG: Session 3747 running command /usr/lib/lightdm/lightdm-greeter-session /usr/share/xgreeters/pantheon-greeter
[+1.70s] DEBUG: Greeter connected version=1.2.3
[+1.70s] DEBUG: Greeter connected, display is ready
[+1.70s] DEBUG: New display ready, switching to it
[+1.70s] DEBUG: Activating VT 7
[+5.20s] DEBUG: Greeter start authentication for bruno
[+5.20s] DEBUG: Started session 4697 with service 'lightdm', username 'bruno'
[+5.20s] DEBUG: Session 4697 got 1 message(s) from PAM
[+5.20s] DEBUG: Prompt greeter with 1 message(s)
[+5.23s] DEBUG: Continue authentication
[+5.29s] DEBUG: Session 4697 authentication complete with return value 0: Success
[+5.29s] DEBUG: Authenticate result for user bruno: Success
[+5.34s] DEBUG: User bruno authorized
[+5.36s] DEBUG: Greeter requests session pantheon
[+5.36s] DEBUG: Using session pantheon
[+5.36s] DEBUG: Stopping greeter
[+5.36s] DEBUG: Session 3747: Sending SIGTERM
[+5.41s] DEBUG: Session 3747 exited with return value 0
[+5.41s] DEBUG: Greeter quit
[+5.43s] DEBUG: Dropping privileges to uid 1000
[+5.43s] DEBUG: Restoring privileges
[+5.45s] DEBUG: Dropping privileges to uid 1000
[+5.46s] DEBUG: Writing /home/bruno/.dmrc
[+5.49s] DEBUG: Restoring privileges
[+5.54s] DEBUG: Starting session pantheon as user bruno
[+5.54s] DEBUG: Session 4697 running command /usr/sbin/lightdm-session gnome-session --session=pantheon
[+5.57s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+5.57s] DEBUG: Greeter closed communication channel

시작 로그

 * Starting RPC portmapper replacement                                        [ OK ]
 * Starting Start this job to wait until rpcbind is started or fails to start [ OK ]
 * Stopping Start this job to wait until rpcbind is started or fails to start [ OK ]
 * Starting mDNS/DNS-SD daemon                                                [ OK ]
 * Stopping rpcsec_gss daemon                                                 [ OK ]
 * Starting NSM status monitor                                                [ OK ]
 * Starting configure network device                                          [ OK ]
 * Stopping Failsafe Boot Delay                                               [ OK ]
 * Starting System V initialisation compatibility                             [ OK ]
 * Starting modem connection manager                                          [ OK ]
 * Starting configure network device security                                 [ OK ]
Skipping profile in /etc/apparmor.d/disable: usr.bin.firefox
Skipping profile in /etc/apparmor.d/disable: usr.sbin.rsyslogd
 * Starting AppArmor profiles                                                 [ OK ]
 * Starting CUPS printing spooler/server                                      [ OK ]
 * Stopping System V initialisation compatibility                             [ OK ]
 * Starting network connection manager                                        [ OK ]
 * Starting System V runlevel compatibility                                   [ OK ]
 * Starting save kernel messages                                              [ OK ]
 * Starting anac(h)ronistic cron                                              [ OK ]
 * Starting regular background program processing daemon                      [ OK ]
 * Starting deferred execution scheduler                                      [ OK ]
 * Starting ACPI daemon                                                       [ OK ]
 * Starting CPU interrupts balancing daemon                                   [ OK ]
 * Stopping anac(h)ronistic cron                                              [ OK ]
 * Starting LightDM Display Manager                                           [ OK ]
 * Stopping Send an event to indicate plymouth is up                          [ OK ]
 * Starting configure network device security                                 [ OK ]
 * Starting configure network device                                          [ OK ]
 * Starting KVM                                                               [ OK ]
 * Stopping save kernel messages                                              [ OK ]