Xinit is not installed and therefor startx is also not a part of VSIDO... I have used startx in the past most likely trying to resolve nVidia issues. Having gone to lightDM and pure nouveau as my drivers I do not miss xinit or startx
For clarity, I am on the build server partition now that had been my main build all through kernel 3.14 and 3.15. It does not have xinit and startx either and until today it has not been used or useful
Log file of lightdm now on failed boot
/var/log/lightdm/lightdm.conf
[+0.03s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.03s] DEBUG: Starting Light Display Manager 1.10.1, UID=0 PID=818
[+0.03s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.03s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/01_debian.conf
[+0.03s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.03s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.03s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.03s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.12s] DEBUG: Registered seat module xlocal
[+0.12s] DEBUG: Registered seat module xremote
[+0.12s] DEBUG: Registered seat module unity
[+0.12s] DEBUG: Registered seat module surfaceflinger
[+0.84s] DEBUG: Adding default seat
[+0.84s] DEBUG: Seat: Starting
[+0.84s] DEBUG: Seat: Creating greeter session
[+0.94s] DEBUG: Seat: Creating display server of type x
[+0.94s] DEBUG: Could not run plymouth --ping: Failed to execute child process "plymouth" (No such file or directory)
[+0.94s] DEBUG: Using VT 7
[+0.94s] DEBUG: Seat: Starting local X display on VT 7
[+0.94s] DEBUG: DisplayServer x-0: Logging to /var/log/lightdm/x-0.log
[+0.94s] DEBUG: DisplayServer x-0: Writing X server authority to /var/run/lightdm/root/:0
[+0.94s] DEBUG: DisplayServer x-0: Launching X Server
[+0.94s] DEBUG: Launching process 910: /usr/bin/X :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.94s] DEBUG: DisplayServer x-0: Waiting for ready signal from X server :0
[+0.94s] WARNING: Could not enumerate user data directory /var/lib/lightdm-data: No such file or directory
[+0.94s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.94s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+2.96s] DEBUG: Got signal 10 from process 910
[+2.96s] DEBUG: DisplayServer x-0: Got signal from X server :0
[+2.96s] DEBUG: DisplayServer x-0: Connecting to XServer :0
[+2.97s] DEBUG: Seat: Display server ready, starting session authentication
[+2.97s] DEBUG: Session pid=1173: Started with service 'lightdm-greeter', username 'lightdm'
[+3.13s] DEBUG: Session pid=1173: Authentication complete with return value 0: Success
[+3.13s] DEBUG: Seat: Session authenticated, running command
[+3.13s] DEBUG: Session pid=1173: Running command /usr/sbin/lightdm-gtk-greeter
[+3.13s] WARNING: Error getting user list from org.freedesktop.Accounts: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.Accounts was not provided by any .service files
[+3.13s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+3.13s] DEBUG: User vastone added
[+3.14s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm
[+3.14s] WARNING: Could not create user data directory /var/lib/lightdm-data/lightdm: Error creating directory: No such file or directory
[+3.14s] DEBUG: Session pid=1173: Logging to /var/log/lightdm/x-0-greeter.log
[+3.40s] DEBUG: Activating VT 7
[+3.40s] DEBUG: Activating login1 session /org/freedesktop/login1/session/c1
[+4.10s] DEBUG: Session pid=1173: Greeter connected version=1.10.1
[+5.53s] DEBUG: Session pid=1173: Greeter start authentication for vastone
[+5.53s] DEBUG: Session pid=1320: Started with service 'lightdm', username 'vastone'
[+5.57s] DEBUG: Session pid=1320: Got 1 message(s) from PAM
[+5.57s] DEBUG: Session pid=1173: Prompt greeter with 1 message(s)
[+9.61s] DEBUG: Session pid=1173: Continue authentication
[+9.64s] DEBUG: Session pid=1320: Authentication complete with return value 0: Success
[+9.64s] DEBUG: Session pid=1173: Authenticate result for user vastone: Success
[+9.64s] DEBUG: Session pid=1173: User vastone authorized
[+9.65s] DEBUG: Session pid=1173: Greeter sets language en_US.utf8
[+9.68s] DEBUG: Session pid=1173: Greeter requests session fluxbox
[+9.68s] DEBUG: Seat: Stopping greeter; display server will be re-used for user session
[+9.68s] DEBUG: Session pid=1173: Sending SIGTERM
[+9.70s] DEBUG: Session pid=1173: Greeter closed communication channel
[+9.70s] DEBUG: Session pid=1173: Exited with return value 0
[+9.70s] DEBUG: Seat: Session stopped
[+9.70s] DEBUG: Seat: Greeter stopped, running session
[+9.70s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+9.70s] DEBUG: Session pid=1320: Running command /etc/X11/Xsession /usr/bin/startfluxbox
[+9.70s] DEBUG: Creating shared data directory /var/lib/lightdm-data/vastone
[+9.70s] WARNING: Could not create user data directory /var/lib/lightdm-data/vastone: Error creating directory: No such file or directory
[+9.70s] DEBUG: Session pid=1320: Logging to .xsession-errors
[+9.92s] DEBUG: Activating VT 7
[+9.92s] DEBUG: Activating login1 session /org/freedesktop/login1/session/_31
[+69555.78s] DEBUG: /etc/passwd changed, reloading user list
[+69555.78s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69555.78s] DEBUG: /etc/passwd changed, reloading user list
[+69555.78s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69555.78s] DEBUG: /etc/passwd changed, reloading user list
[+69555.78s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69555.78s] DEBUG: /etc/passwd changed, reloading user list
[+69555.78s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69555.78s] DEBUG: /etc/passwd changed, reloading user list
[+69555.78s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69555.78s] DEBUG: /etc/passwd changed, reloading user list
[+69555.78s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69555.78s] DEBUG: /etc/passwd changed, reloading user list
[+69555.78s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69556.78s] DEBUG: /etc/passwd changed, reloading user list
[+69556.78s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69556.78s] DEBUG: /etc/passwd changed, reloading user list
[+69556.78s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69556.78s] DEBUG: /etc/passwd changed, reloading user list
[+69556.78s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69556.78s] DEBUG: /etc/passwd changed, reloading user list
[+69556.78s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69556.78s] DEBUG: /etc/passwd changed, reloading user list
[+69556.78s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69556.79s] DEBUG: /etc/passwd changed, reloading user list
[+69556.79s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69556.79s] DEBUG: /etc/passwd changed, reloading user list
[+69556.79s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69556.79s] DEBUG: /etc/passwd changed, reloading user list
[+69556.79s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69556.79s] DEBUG: /etc/passwd changed, reloading user list
[+69556.79s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69557.79s] DEBUG: /etc/passwd changed, reloading user list
[+69557.79s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69557.79s] DEBUG: /etc/passwd changed, reloading user list
[+69557.79s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69557.79s] DEBUG: /etc/passwd changed, reloading user list
[+69557.79s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69557.79s] DEBUG: /etc/passwd changed, reloading user list
[+69557.79s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69557.79s] DEBUG: /etc/passwd changed, reloading user list
[+69557.79s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69557.79s] DEBUG: /etc/passwd changed, reloading user list
[+69557.79s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69557.80s] DEBUG: /etc/passwd changed, reloading user list
[+69557.80s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69557.80s] DEBUG: /etc/passwd changed, reloading user list
[+69557.80s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69557.80s] DEBUG: /etc/passwd changed, reloading user list
[+69557.80s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69557.80s] DEBUG: /etc/passwd changed, reloading user list
[+69557.80s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69558.81s] DEBUG: /etc/passwd changed, reloading user list
[+69558.81s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+69558.81s] DEBUG: /etc/passwd changed, reloading user list
[+69558.81s] DEBUG: Loading user config from /etc/lightdm/users.conf
Log file on a good working boot of lightdm (this machine I am on)
/var/log/lightdm/lightdm.conf
[+0.03s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.03s] DEBUG: Starting Light Display Manager 1.10.1, UID=0 PID=909
[+0.03s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.03s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/01_debian.conf
[+0.03s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.03s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.03s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.03s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.06s] DEBUG: Registered seat module xlocal
[+0.06s] DEBUG: Registered seat module xremote
[+0.06s] DEBUG: Registered seat module unity
[+0.06s] DEBUG: Registered seat module surfaceflinger
[+0.75s] DEBUG: Adding default seat
[+0.75s] DEBUG: Seat: Starting
[+0.75s] DEBUG: Seat: Creating greeter session
[+0.79s] DEBUG: Seat: Creating display server of type x
[+0.79s] DEBUG: Could not run plymouth --ping: Failed to execute child process "plymouth" (No such file or directory)
[+0.79s] DEBUG: Using VT 7
[+0.79s] DEBUG: Seat: Starting local X display on VT 7
[+0.79s] DEBUG: DisplayServer x-0: Logging to /var/log/lightdm/x-0.log
[+0.79s] DEBUG: DisplayServer x-0: Writing X server authority to /var/run/lightdm/root/:0
[+0.79s] DEBUG: DisplayServer x-0: Launching X Server
[+0.79s] DEBUG: Launching process 1165: /usr/bin/X :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.79s] DEBUG: DisplayServer x-0: Waiting for ready signal from X server :0
[+0.79s] WARNING: Could not enumerate user data directory /var/lib/lightdm-data: No such file or directory
[+0.79s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.79s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+2.37s] DEBUG: Got signal 10 from process 1165
[+2.37s] DEBUG: DisplayServer x-0: Got signal from X server :0
[+2.37s] DEBUG: DisplayServer x-0: Connecting to XServer :0
[+2.37s] DEBUG: Seat: Display server ready, starting session authentication
[+2.37s] DEBUG: Session pid=1171: Started with service 'lightdm-greeter', username 'lightdm'
[+2.60s] DEBUG: Session pid=1171: Authentication complete with return value 0: Success
[+2.60s] DEBUG: Seat: Session authenticated, running command
[+2.60s] DEBUG: Session pid=1171: Running command /usr/sbin/lightdm-gtk-greeter
[+2.60s] WARNING: Error getting user list from org.freedesktop.Accounts: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.Accounts was not provided by any .service files
[+2.60s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+2.60s] DEBUG: User vastone added
[+2.63s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm
[+2.63s] WARNING: Could not create user data directory /var/lib/lightdm-data/lightdm: Error creating directory: No such file or directory
[+2.63s] DEBUG: Session pid=1171: Logging to /var/log/lightdm/x-0-greeter.log
[+3.33s] DEBUG: Activating VT 7
[+3.33s] DEBUG: Activating login1 session /org/freedesktop/login1/session/c1
[+4.75s] DEBUG: Session pid=1171: Greeter connected version=1.10.1
[+6.01s] DEBUG: Session pid=1171: Greeter start authentication for vastone
[+6.01s] DEBUG: Session pid=1280: Started with service 'lightdm', username 'vastone'
[+6.06s] DEBUG: Session pid=1280: Got 1 message(s) from PAM
[+6.06s] DEBUG: Session pid=1171: Prompt greeter with 1 message(s)
[+9.68s] DEBUG: Session pid=1171: Continue authentication
[+9.71s] DEBUG: Session pid=1280: Authentication complete with return value 0: Success
[+9.71s] DEBUG: Session pid=1171: Authenticate result for user vastone: Success
[+9.71s] DEBUG: Session pid=1171: User vastone authorized
[+9.72s] DEBUG: Session pid=1171: Greeter sets language en_US.utf8
[+9.78s] DEBUG: Session pid=1171: Greeter requests session fluxbox
[+9.78s] DEBUG: Seat: Stopping greeter; display server will be re-used for user session
[+9.78s] DEBUG: Session pid=1171: Sending SIGTERM
[+9.80s] DEBUG: Session pid=1171: Greeter closed communication channel
[+9.80s] DEBUG: Session pid=1171: Exited with return value 0
[+9.80s] DEBUG: Seat: Session stopped
[+9.80s] DEBUG: Seat: Greeter stopped, running session
[+9.80s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+9.80s] DEBUG: Session pid=1280: Running command /etc/X11/Xsession /usr/bin/startfluxbox
[+9.80s] DEBUG: Creating shared data directory /var/lib/lightdm-data/vastone
[+9.80s] WARNING: Could not create user data directory /var/lib/lightdm-data/vastone: Error creating directory: No such file or directory
[+9.80s] DEBUG: Session pid=1280: Logging to .xsession-errors
[+10.08s] DEBUG: Activating VT 7
[+10.08s] DEBUG: Activating login1 session /org/freedesktop/login1/session/_31
[+1694.25s] DEBUG: Process 1165 terminated with signal 6
[+1694.25s] DEBUG: DisplayServer x-0: X server stopped
[+1694.25s] DEBUG: Releasing VT 7
[+1694.25s] DEBUG: DisplayServer x-0: Removing X server authority /var/run/lightdm/root/:0
[+1694.25s] DEBUG: Seat: Display server stopped
[+1694.25s] DEBUG: Seat: Stopping session
[+1694.25s] DEBUG: Session pid=1280: Sending SIGTERM
[+1694.25s] DEBUG: Seat: Active display server stopped, starting greeter
[+1694.25s] DEBUG: Seat: Creating greeter session
[+1694.25s] DEBUG: Seat: Creating display server of type x
[+1694.25s] DEBUG: Using VT 7
[+1694.25s] DEBUG: Seat: Starting local X display on VT 7
[+1694.25s] DEBUG: DisplayServer x-0: Logging to /var/log/lightdm/x-0.log
[+1694.25s] DEBUG: DisplayServer x-0: Writing X server authority to /var/run/lightdm/root/:0
[+1694.25s] DEBUG: DisplayServer x-0: Launching X Server
[+1694.25s] DEBUG: Launching process 4482: /usr/bin/X :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+1694.25s] DEBUG: DisplayServer x-0: Waiting for ready signal from X server :0
[+1694.30s] DEBUG: Session pid=1280: Exited with return value 15
[+1694.30s] DEBUG: Seat: Session stopped
[+1694.30s] DEBUG: Seat: Stopping display server, no sessions require it
[+1694.58s] DEBUG: Got signal 10 from process 4482
[+1694.58s] DEBUG: DisplayServer x-0: Got signal from X server :0
[+1694.58s] DEBUG: DisplayServer x-0: Connecting to XServer :0
[+1694.59s] DEBUG: Seat: Display server ready, starting session authentication
[+1694.59s] DEBUG: Session pid=4494: Started with service 'lightdm-greeter', username 'lightdm'
[+1694.60s] DEBUG: Session pid=4494: Authentication complete with return value 0: Success
[+1694.60s] DEBUG: Seat: Session authenticated, running command
[+1694.60s] DEBUG: Session pid=4494: Running command /usr/sbin/lightdm-gtk-greeter
[+1694.60s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm
[+1694.60s] WARNING: Could not create user data directory /var/lib/lightdm-data/lightdm: Error creating directory: No such file or directory
[+1694.60s] DEBUG: Session pid=4494: Logging to /var/log/lightdm/x-0-greeter.log
[+1694.62s] DEBUG: Activating VT 7
[+1694.62s] DEBUG: Activating login1 session /org/freedesktop/login1/session/c2
[+1694.70s] DEBUG: Session pid=4494: Greeter connected version=1.10.1
[+1695.03s] DEBUG: Session pid=4494: Greeter start authentication for vastone
[+1695.03s] DEBUG: Session pid=4523: Started with service 'lightdm', username 'vastone'
[+1695.04s] DEBUG: Session pid=4523: Got 1 message(s) from PAM
[+1695.04s] DEBUG: Session pid=4494: Prompt greeter with 1 message(s)
[+4905.37s] DEBUG: Session pid=4494: Continue authentication
[+4905.39s] DEBUG: Session pid=4523: Authentication complete with return value 0: Success
[+4905.39s] DEBUG: Session pid=4494: Authenticate result for user vastone: Success
[+4905.39s] DEBUG: Session pid=4494: User vastone authorized
[+4905.41s] DEBUG: Session pid=4494: Greeter sets language en_US.utf8
[+4905.45s] DEBUG: Session pid=4494: Greeter requests session fluxbox
[+4905.45s] DEBUG: Seat: Stopping greeter; display server will be re-used for user session
[+4905.45s] DEBUG: Session pid=4494: Sending SIGTERM
[+4905.47s] DEBUG: Session pid=4494: Greeter closed communication channel
[+4905.47s] DEBUG: Session pid=4494: Exited with return value 0
[+4905.47s] DEBUG: Seat: Session stopped
[+4905.47s] DEBUG: Seat: Greeter stopped, running session
[+4905.47s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session1
[+4905.48s] DEBUG: Session pid=4523: Running command /etc/X11/Xsession /usr/bin/startfluxbox
[+4905.48s] DEBUG: Creating shared data directory /var/lib/lightdm-data/vastone
[+4905.48s] WARNING: Could not create user data directory /var/lib/lightdm-data/vastone: Error creating directory: No such file or directory
[+4905.48s] DEBUG: Session pid=4523: Logging to .xsession-errors
[+4905.50s] DEBUG: Activating VT 7
[+4905.50s] DEBUG: Activating login1 session /org/freedesktop/login1/session/_33
I am working now on changing the lightdm-gtk-greeter.conf around to see if that makes a difference