Disable graphical interfaces in Ubuntu12.04

Background for disabling the graphic interface under Ubuntu12.04 1. Ubuntu runtime Linux systems run at a specified runtime level at any time, and different runtime-level programs and services are different, the work to be done and the purpose to be achieved are different, the system can be in... background knowledge about disabling graphical interfaces in Ubuntu 12.04 1. Ubuntu runtime Linux systems run at a specified runtime level at any time, in addition, different running-level programs and services are different, and the work to be done and the purpose to be achieved are different. The system can switch between these running-level programs to complete different work. Ubuntu system running level: * 0: Shutdown level * 1: Single User running level, run rc. script 2 in the sysinit and rc1.d directories: multiple users, but NFS is not started. in some linux systems, level 2 is the default mode and has network functions, such as ubuntu. debian * 3: Multi-user, character mode, system startup with network functions, redhat Common run level * 4: user-defined level * 5: graphic interface mode, redhat Common run level * 6: restart level * S: a single user running level. Only rc is run. sysinit File 2. view the current running level and run the command: runlevel (runlevel shows the last running level and the current running level. "N" indicates that the last running level is not displayed .) 3. switch the running level and run the command: int [0123456Ss] (that is, the init command is followed by a parameter. this parameter is the running level code to switch to, for example: shut down with the init 0 command; restart with the init 6 command .) Switch crtl + alt + F1 ~ F7F1 ~ F6 is the console with 6 characters. F7 returns to the graphic interface console Ubuntu12.04 and starts to directly enter the character interface: modify the GRUB configuration file (it is best not to change grub directly. conf)/etc/default/grub replace GRUB_CMDLINE_LINUX_DEFAULT = "quiet splash" with GRUB_CMDLINE_LINUX_DEFAULT = "text" and save the file to sudo update-grub. grub is updated. conf restart Ubuntu12.04 character interface start graphical interface: startx