Ubuntu Default boot RunLevel is 2, you can use RunLevel to view the current default run level.
The runlevel level is defined as follows: 0–halt, shutdown mode 1–single, single user mode 2-full multi-user with Display Manager (GUI) 3-full multi-user with display Manager (GUI) 4-full multi-user with display Manager (GUI) 5-full multi-user with display Manager (GUI) 6–reboot, rebootyou can see that there is no difference in the 2~5 level. Linux different from the Redhat kernel
The default RunLevel file for Ubuntu is/etc/init/rc-sysinit.conf.
Prevent default graphics desktop from starting Ubuntu 12.04 the default open opportunity enters a graphical interface that is implemented by the LIGHTDM process. The first thing to do is to stop this LIGHTDM process from booting up. Procedure: (1), view file/etc/init/rc-sysinit.conf, near line 14th: Confirm "env default_runlevel=2". 2 is the default for the newly installed system, ensuring that it is not modified. (2), edit the file/etc/init/lightdm.conf, near the 12th line, the original sentence "and RunLevel [!06]" to "and RunLevel [!026]".
Ubuntu 14 Modify startup mode off start graphical interface