Cfrgtkky

While it's ubuntu for Ubuntu live images it also depends on the flavor. For Edubuntu it's edubuntu.

Known users and passwords so far (nothing after a colon means a blank password):

• Ubuntu: ubuntu:
  


• Kubuntu: kubuntu:
  


• Lubuntu: lubuntu:
  


• LXLE: qwerty:
  


• Ubuntu-studio: ubuntu-studio:
  


• Edubuntu: edubuntu:
  


• ChaletOS: chaletos-user:
  


• Xubuntu: xubuntu:
  


• Ubuntu Mate: ubuntu-mate:
  

18.04

This is an answer to a very old question. None of the above have ever worked for me.

The last time I had this problem was after trying to move "home" from / to /home using cut and paste, (I was in a rush).

After using rsync to move home, the problem went away.

I have previously seen this problem caused mostly by bad persistence files.

• Confirm MD5SUM.




• Check if the problem persists with a live boot (non-persistent).




• Confirm there is space in the casper-rw file or partition.




• Try a different boot disk creator program.




• Try the USB stick on a different computer.

Exceptions:

Syslinux type installers including Rufus, Startup Disk Creator, UNetbootin, Universal and YUMI do not use ubuntu as the default user, they use Live session user instead.

For these installers after logging out you can hit enter to log back in.
After a suspend simply pressing the power button brings you back to desktop.

Grub type installers, ie mkusb also use Live session user as user and a blank password when logging back in. After a suspend simply pressing the power button brings you back to desktop.

Live CD/DVD also uses Live session user for user name, it is supplied automatically. After logging out, a password is not asked for when logging back in. After suspend, pressing the power button will bring you back to desktop.

In summary, under normal circumstances, no user name or password should need to be entered when logging into 18.04 CD/DVD and Live or Persistent USB's

Rewriting the same image to USB a second time prevented the login screen from appearing.

I had the same issue on an HP Elitebook Folio 1040 with the standard 16.04.1 image, downloaded and copied to USB with usb-creator-gtk 0.2.23. None of the above mentioned username/password combinations worked for me.

I have encountered this issue and here is how I worked around this issue:

If the username is "ubuntu" as it should be and if no password is needed to execute a sudo command, you will still be asked for a password after logging out when logging back in and a blank password usually won't work here.

To get around this, just open a terminal and execute the following command:

sudo passwd ubuntu

follow the prompts and set a password; the current password is blank so if it asks for a password here or for sudo, just press enter.

Now, when the system asks for a password, you will have one and this should work around your problem.

You may need to execute this command from TTY1 or 2.

Not blank...example in 14.10 live I installed xfce4 then logged out. Had to add a user. To do so press Ctrl+Alt+F2. You should now see a console. Type sudo adduser anyname and follow the instructions. Afterwards press Ctrl+Alt+F7. You should be at the graphic login able to use the info you created.

It seems that for some reason in Ubuntu 18.04 Desktop the install media which I just downloaded and verified via md5, and sha256 hashes along with using the gpg signatures to validate the md5, and sha256 hashes from http://mirror.math.princeton.edu/pub/ubuntu-iso/18.04/ubuntu-18.04-desktop-amd64.iso that you can not utilize the tty[2-4] as in past installer executions. The tty2 screen is now asking for a username/password pair to access tty2 which is NOT ubuntu:{no-password}. Please not that in the past that tty[1-4] were non GUI (tty1 was for dmesg logging for errors thrown while installing, however tty[2-4] were usually available to the user to access the command line, tty7 was generally set aside as the graphical interface for the installer up through 16.x while 17.x and newer moved the graphical installer screen to tty1) and defaulted to a sh/bash or similar command shell without any username/password login. As there is a definite use for having access to the command line while installing I would recommend a check that this is indeed the desired action to have while the installer is running.

Further testing of usernames failed to allow me into the terminal. Usernames I tried were and yet all listed below failed the username/password check.
root:root
root:{no-password}
ubuntu:{no-password}
ubuntu:ubuntu
Ubuntu:{no-password}
Ubuntu:Ubuntu

I got around this issue by moving the mouse around until it completed its boot cycle. It looks like the screen is locking, that is why it wants the password. By continuously moving the mouse, the screen never locked.

Perhaps the Ubuntu devs should consider changing the setting so that the screen does not lock or it does not require a password when it is locked.