In Ubuntu 15.04 can't do graphical log in

Question

I have done clean install recently of Ubuntu Desktop 15.04.
And I was able to log in to the graphical environment until I enabled "boot to text" like said there: How do I disable X at boot time so that the system boots in text mode?
1. commented out

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

2. added "text" to

GRUB_CMDLINE_LINUX="text"

3. uncommented

GRUB_TERMINAL=console

4.

sudo update-grub

5.

sudo systemctl set-default multi-user.target

Now system does not load gui, just text prompt.
When I want the GUI, I start it using

sudo systemctl start lightdm

graphical login prompt appear, but when I pass the password screen flickers and again password prompt appears.
I even reverted all changes back: grub file and

sudo systemctl set-default graphical.target

How can I log in to the GUI now, please?

Solution 1

To solve my problem I have to change ownership of .Xauthority file from root to my user like this:

chown myusername:myusername .Xauthority

where myusername is my username.

Solution 2

Based on the bug report, reported March 21, 2015 Ubuntu 15.04 Xserver does not start or freezes with systemd + lightdm. More detail regarding the impact of this change and how to switch from systemd to upstart and back again is available on this page.

To check to see if your system is using systemd vs. upstart you can test by issuing the command sudo initctl version which will return upstart if upstart is handling init. another useful method is to issue the command dpkg -S /sbin/init which will tell you which package installed it (in my case on 14.04 it's upstart) you can find more very good answers on how to do so from our friends at Unix & Linux. Further detail regarding identifying the init system is also available.

To see if your lightdm works under upstart as designed, you can install the upstart-sysv package, which will remove ubuntu-standard and systemd-sysv (but should not remove anything else. Give the developers a heads up if it does!), and run sudo update-initramfs -u. After that, grub's "Advanced options" menu will have a corresponding "Ubuntu, with Linux ... (systemd)" entry where you can do an one-time boot with systemd.

You can revert back to systemd installing systemd-sysv and ubuntu-standard packages.

Another option appears to be to use gdm under systemd instead of lightdm under upstart.

Further sources (not linked elsewhere):

https://unix.stackexchange.com/questions/196166/how-to-find-out-if-a-system-uses-sysv-upstart-or-systemd-initsystem

Solution 3

I am also having problems with lightdm refusing to show up. In my case, I have both "plain" ubuntu and kubuntu-desktop, so I chose sddm as login screen (sudo dpkg-reconfigure lightdm allowed me to select which login manager I wanted). Maybe installing sddm (if you don't want all of Kubuntu desktop) might be a workaround (I don't know detailed steps on how to install and configure ONLY sddm, though). I'm on a Haswell integrated graphics setup.

gdm seems to work, too: https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/1434799

Solution 4

I had this problems after upgrading from 14.04. I restarted the system and went in to a terminal and tested the login at the terminal and determined my logins worked. I logged in as root and did apt-get update and saw an error that stated that I needed to run dpkg --configure -a. I ran the command and let it reconfigure the system. After it was finished( about an hour) I rebooted the system and was able to log in to the graphical login.

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Comments

[Admin]

Similar questions are askubuntu.com/questions/613577 and askubuntu.com/questions/613701 .

[Admin]

Screen flicks only when I type in password and hit enter. And do not have NVidia. I have Ubuntu in Hyper-V Gen2 virtual machine.

[Admin]

Sure @ElderGeek