In this mode, the Ubuntu graphical user interface is not loaded. No graphics drivers are loaded either. Apart from the graphical user interface, all Ubuntu functions are available.

This can be helpful if the graphic driver or the graphical user interface causes problems when booting. This may also be desirable with a real-time system. The latencies of the system are reduced as no resources are used for the graphical user interface. Also the graphic driver cannot bring in any additional jitter.

If you want to boot with only the most basic fetures of Ubuntu, choose RunLevel 1.

Detailed article

1. sudo nano /etc/default/grub
2. Set these parameters:
   1. GRUB_CMDLINE_LINUX_DEFAULT=„text“
   2. GRUB_TERMINAL=console
3. sudo update-grub
4. sudo systemctl set-default multi-user.target
5. Reboot

1. sudo systemctl set-default graphical.target
2. Reboot

Debian Doku for RunLevel

Linux starts different servicec as different RunLevels. Depending on the RunLevel different services are available:

• RunLevel 1: Single-user mode. Most basic mode. Only textconsole available.
• RunLevel 2: Multi-user mode. You can now use different users.
• RunLevel 3: Networking is now available.
• RunLevel 4: Reserved.
• RunLevel 5: Starts the GUI. This is the normal RunLevel.

This will change the RunLevel only for one startup.

1. Reboot
2. In the GRUB menue press 'e' to edit the boot configuration
3. Add a single '1' (for RunLevel 1) to the end of the line, which starts with linux

   linux	/vmlinuz-3.5.0-54-generic root=/dev/mapper/faramir-root ro 1

4. Press F10 to boot

This does not work on all Systems. Ubuntu does not seem to like this method. But it works on more basic system like on a Beagle Bone.

1. sudo init 1