Booting into text mode console in Ubuntu 12.04.

I have found out how to stop the graphical login manager and get to a plain text console in Ubuntu, you type this command as root and it will shutdown the Lightdm login manager. Press Ctrl-Alt-F2 and login at the text console then type the command to get rid of the login manager.

sudo stop lightdm

This command will shut down the login manager and allow you to use the framebuffer console to perform tasks such as installing Nvidia drivers that require Xorg to be shut down. The grub.cfg entry should look like this, just make a copy of the existing entry for your distribution and give it a new name. Then for the linux line, remove the quiet splash commands and change it to text. And change vt.handoff from 7 to 1, this will dump you at the 1st virtual console and then you may login to your text console. If you wish to start the login manager then type sudo start gdm or sudo start lightdm depending on whichever graphical login manager you have installed.

menuentry 'Ubuntu, with Linux 3.2.0-8-generic console login' --class ubuntu --class gnu-linux --class gnu --class os {
	set gfxpayload=$linux_gfx_mode
	insmod gzio
	insmod part_msdos
	insmod ext2
	set root='(hd0,msdos1)'
	search --no-floppy --fs-uuid --set=root 7962f1b3-1c9c-4966-825e-f0b964a3dfdc
	linux /boot/vmlinuz-3.2.0-8-generic root=UUID=7962f1b3-1c9c-4966-825e-f0b964a3dfdc ro text vt.handoff=1
	initrd	/boot/initrd.img-3.2.0-8-generic

This is a nice alternative to the old /etc/inittab system that Red Hat distributions used.