URGENT:::: Linux system not loading up login page....

[hassan_haq]

Hi,
I've been using Linux (on my laptop Dell latitude E6440) for around a year now and during this time the operating system has been working completely fine up until yesterday. For some reason Linux no longer boots up & instead after showing the Ubuntu loading screen keeps looping through an alternation of a black screen followed by a screen with some writing on it. The written screen that is looped over is slightly different each time I re-boot my laptop.
I've attached below pictures of the written screen that is continuously looped over when I try and start my Linux system. From what I can deduce, I think the GNOME Display manager is not functioning correctly. (My reasoning is that the GNOME Display Manager is always mentioned in the last line of the screen that is looped over). Hence would removing and re-installing GNOME Display Manager solve the issue that I am having? If so how do I remove and re-install it?

Also I'd like to add that if I load up the Linux system through recovery mode (after going into the grub loader) & then resume normal boot, my laptop just shows a loop of an alternation between the screen switching off and a dark black screen.


I would appreciate it a lot if a solution to my issue could be given as soon as possible as I have a lot work that I cannot start until I get my Linux system to work.

Thanks in advance for any help given.

 

[Alexzee]

What happened yesterday? Did your distro start doing this after an update?
Where you trying to install something?

What Linux distribution are you running?

Can you get to a terminal by pressing CTRL + ALT + F1 or F2?

 

[hassan_haq]

I think I've installed quite a few different software recently, mainly related to simulating molecular dynamics (e.g. Tinker). After following advice online, I think I may have updated my Linux system as I was having problems downloading certain software. I think maybe at time I was just copying in pieces of coding online into the Linux terminal to get the software to work not knowing myself what the actual code was doing. I'm not sure if this is the reason why my system is not loading up anymore.
I'm currently using Ubuntu 20.04.1 LTS.
I can get to a terminal by pressing CTRL + ALT + F1 or F2. However I can't remember what the username is for my account. Every time I logged in I always entered my password so I wasn't aware I had a username. Is there any way to find out my username using the terminal window that I can access after selecting the root option on the recovery menu (that shows up after loading up the Linux system through recovery mode)?

 

[Jared.]

Your username would most your first name (assuming you entered your actual name in the menu when initially installing the distribution) in all common letters. You could also go to recovery mode and type: ls /home which would allow you to view the users on your computer and hence the usernames.

Afterwards you can try reinstalling gdm or using the startx command under tty (you gain access to the tty when pressing CTRL + Alt + F2).

 

[wizardfromoz]

G'day I would be more inclined, given Hassan has access to recovery mode through the Grub Menu, to use that to reinstall Grub and see what happens.

I'll give a blow by blow in the following Post, just wanted to put this on pause.

Wizard

 

[wizardfromoz]

(Wizard appears in a puff of smoke, bearing stone tablets of instructions, drops one on his toes, won't describe what he says)

Depending on what part of the world you are, I would try this when you are fresh, but it's your call.

1. On the Grub Menu, in the Advanced Options choose Recovery mode as you apparently have done previously but this time move down to Drop to Root Shell prompt and press Enter

2. There choose Press Enter for Maintenance, not Ctrl D

3. You will have a prompt with a # at the start, you are now Root, no need for UserID. Type in and enter

lsblk

that's l for Lima, s for Sierra, b for Bravo, l for Lima, k for Kilo

This will show you your drive and partition setup, and there will be a forward slash / against the partition you are on, where your Ubuntu is installed, that is your small r root (operating system)

4. We would then use the device, not the partition number to issue the following command. For example if the forward slash was against /dev/sda2

grub-install /dev/sda

That hopefully will result in an OK.

Then

5.

reboot

and let us know how you go.

I don't believe GDM has necessarily anything to do with it.

Cheers

Chris Turner
wizardfromoz

 

[hassan_haq]

Hi,
Thank you all for all the effort and time you've put into your replies. As suggested by Jared I have accessed tty and tried reinstalling gdm3 and then rebooting the Linux system thereafter. I used the following coding to do so:
sudo apt install --reinstall gdm3 ubuntu-desktop gnome-shell
systemctl reboot
However, unfortunately, this did not fix the problem.
I also followed wizardfromoz's advice but this also does not fix the problem.

To try and the fix the problem myself, I tried to install lightdm and use this over gdm3. The coding for this is as shown below:
sudo apt-get install lightdm
sudo dpkg-reconfigure lightdm

Using lightdm I was able to get to a login page. However I can't seem to login even though I have the correct password. In particular when I type in a password that is incorrect, a small message in red writing appears above the password box stating: "Invalid password, please try again". When I type in the password I know to be true (as this is the same password that I've used to login via tty), no error message appears and the screen goes black momentarily and then returns back to the login page. When entered correctly, the system accepts my password but for some reason takes me back to the login page. (I know that the system has accepted my password as when I try to reboot the system through tty, I am informed that I am logged in to one of my accounts and therefore must use the command systemctl reboot -i to reboot). If the system has accepted my password why does it take me back to login page? I have updated my system using sudo apt update/upgrade hoping this would solve the problem but it doesn't.

Also I'd like to add that, using the following coding: ls -lh /home/, I have checked the ownership on the /home/username directory and it has not been changed to root . Apparently this is a common reason why login loops occur but unfortunately this does not apply in my case.

 

[wizardfromoz]

Bummer that the grub-install did not work, but you have done very well with your efforts.

I don't suppose you had/have Timeshift installed? If so, you could have just rolled back to before when you performed those updates and software changes.

Other than that, I would be looking to copy what you need from your Home folder/partition for your work and reinstall.

Others might have better suggestions.

Wizard

 

[hassan_haq]

I'm currently trying to re-install my Linux system. I am copying all my work/files from the home directory onto my USB (32GB worth of information). For the files to be copied onto my USB I have used the following coding:
cp -a /<source>/. /<destination>/

Although the files are being copied onto my USB, for every file that is copied I receive the following message: "cp: failed to preserve ownership for '<filename>': Operation not permitted".
I'm not sure what it means by preserving the ownership of the file. Is this something I need to be worried about or can I overlook this message as irrelevant?
Also it is taking a large amount of time to copy all the data (around 2 hours now & still continuing). I do understand that I am copying 32 GB of data which is a large amount but I was wondering if there might be a more efficient, quicker way to copy the data. Also I was wondering if there is a way to get an estimate of the time required to copy the remaining files.
Thanks for all the help.

 

[wizardfromoz]

rsync might be better, and faster but I am no expert in it.

https://linuxhint.com/rsync_copy_files_ubuntu/

Wizard

 

[Deleted member 108694]

(Wizard appears in a puff of smoke, bearing stone tablets of instructions, drops one on his toes, won't describe what he says)

Depending on what part of the world you are, I would try this when you are fresh, but it's your call.

1. On the Grub Menu, in the Advanced Options choose Recovery mode as you apparently have done previously but this time move down to Drop to Root Shell prompt and press Enter

2. There choose Press Enter for Maintenance, not Ctrl D

3. You will have a prompt with a # at the start, you are now Root, no need for UserID. Type in and enter

lsblk

that's l for Lima, s for Sierra, b for Bravo, l for Lima, k for Kilo

This will show you your drive and partition setup, and there will be a forward slash / against the partition you are on, where your Ubuntu is installed, that is your small r root (operating system)

4. We would then use the device, not the partition number to issue the following command. For example if the forward slash was against /dev/sda2

grub-install /dev/sda

That hopefully will result in an OK.

Then

5.

reboot

and let us know how you go.

I don't believe GDM has necessarily anything to do with it.

Cheers

Chris Turner
wizardfromoz

I think it should be

sudo grub-install /dev/sda

 

[wizardfromoz]

No your Lordship, the facility is for you to enter a shell as Root, and it drops you to a prompt with a # signifying that, so no need for sudo.

I have used it dozens of times

Wiz

 

[wizardfromoz]

Damn, I DID forget one thing.

@hassan_haq

following

grub-install /dev/sdx (where x is a letter from a to whatever)

I should have had you run

update-grub

then

reboot

Don't know if you want to try it again

Wiz

 

[Deleted member 108694]

Damn, I DID forget one thing.

@hassan_haq

following

grub-install /dev/sdx (where x is a letter from a to whatever)

I should have had you run

update-grub

then

reboot

Don't know if you want to try it again

Wiz

Y

No your Lordship, the facility is for you to enter a shell as Root, and it drops you to a prompt with a # signifying that, so no need for sudo.

I have used it dozens of times

Wiz

No your Lordship, the facility is for you to enter a shell as Root, and it drops you to a prompt with a # signifying that, so no need for sudo.

I have used it dozens of times

Wiz

Yep you are correct did not pay attention to the # - getting old I guess missed it.

 

[Alexzee]

We all forget stuff sometimes Wizard.
The good thing is that you remembered-