I'm at a loss how to accomplish this. The lab states that: "On some other systems (including Ubuntu) you need to append text instead." But this doesn't help me. I'm sure that someone before me has figured this out.
Took some google-ing, but i found that inserting "text" right after ro, then hitting "ctrl+x" will boot you into a command line. (*don't know if that was the proper method but it worked)*then your next step is getting back to the gui. I won't give away the answer but I will tell you after my attempts, loging in to the gui doesn't work for me. Glad I was able to answer your Question but now I need to go find the answer to mine.
Do you see the grub menu, so you can edit the boot line? Or do you see a black screen and the OS just boots until you get the GUI?
You can start checking this Ubuntu documentation:
I was able to boot in text mode after inserting text as KWick suggested (I'm using pre-configured Ubuntu 14), but failed to start graphical mode. sudo startx show only blue screen, without login prompt.
if you can login as the normal user, do not do "sudo startx"; that would try to give you a GUI as root, not your normal user account. Just say startx.
If that fails, try to restart lightdm (with sudo) which is the display manager, which should take you back to full graphical login
if you using Ubuntu in a VM you have to push ESC from start of the VM. Then the boot menu appeaars and you can choose the kernel you want to start with the arrow keys. After choosing click "e" and you are entering the edit mode. Then search the line where the kernel is loading (starts with kernel vmlinuz....). At the end of this line put a number for a nongrafical runlevel or under Ubuntu you can also use "Single", "s" or "S" instead. After editing push F10 and the system should boot into the choosen runlevel.
Hello...I pushed Esc from the start over and over again. It worked! Thank you. I found my way into GRUB. Thank you, again.
Hello...my non-graphical mode did not run after following this procedure. I did get to GRUB and I found out a little about it. I tried to put an "s" after the end of the line where I could find a "vmlinuz" but I pressed F10 and it booted in graphical mode.
Modifying the grub line should change that boot event only. After restarting the system, does this boot into graphical mode?
Not yet. I am still trying to find time. Sorry for the delay. I will get on it soon.
Hello...I cannot update the grub file in /etc/default to change the file and save it. I have a permission denied error.
Sir/Ma'am...I got the text mode to work on Ubuntu 16.04 in my hypervisor (VMware). I had to change out some files in the etc/default directory, i.e. the grub file specifically. I changed it, saved it, and rebooted. I got to graphical mode afterwards with sudo telinit 5.
I'm glad to know that you were able to solve this.