Prevent GUI login ubuntu

no_gui_boot.md

Edit /etc/default/grub with your favourite editor, e.g. vi:

sudo vi /etc/default/grub

Find this line:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

Change it to:

GRUB_CMDLINE_LINUX_DEFAULT="text"

Update GRUB:

sudo update-grub

For systems that use systemd

This is an additional step for systemd releases, e.g. Ubuntu 15.04, the steps above for grub are still necessary. You need to tell systemd to not load the graphical login manager:

sudo systemctl enable multi-user.target --force
sudo systemctl set-default multi-user.target

Another method (for systemd)

 echo  "manual" | sudo tee -a /etc/init/lightdm.override