LightDM / MDM / Session problems after upgrading to 18.2

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blum
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LightDM / MDM / Session problems after upgrading to 18.2

Post by blum » Wed Jul 05, 2017 4:08 pm

I don't know if this is the right forum? But here it goes:

I upgraded to 18.2 following the guide - also switching to LightDM.
After rebooting I can not log into my account. The session simply does not start. I get the login screen again. I can log into the Guest account though.

Switched back to MDM – but when I log in the GUI is soooooo slooooow Did not use to be that way.
Also the GUI is fast/responsive when using the guest account thru LightDM.

Help to resolve this is much appreciated.

Best regards
Troels

DAMIEN1307
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Re: LightDM / MDM / Session problems after upgrading to 18.2

Post by DAMIEN1307 » Wed Jul 05, 2017 6:38 pm

hi blum...i ran into this problem myself when i did the upgrade through the update manager...1st off lightdm does not get installed in the update /upgrade nor does the kernel update to 4.8 from 4.4 series...app armour as well...i followed clems instructions to the letter to install the lightdm with slick-greeter and then uninstall mdm and then sudo reboot...well all i can say is it borked hardcore...wouldnt go into session it just stayed on the little green LM loadup logo...wouldnt even get to the sign in screen...could just be something with my particular system that didnt take too kindly to that...fortunatley for me i never install anything such as docs, music, videos etc to my HD...all my wants and needs are stored on usb drives...just plug it in and let it rip when i need something other than web browsing...only the operating system is on my HD...after horsing around with it for an hour or so, i took the easy way out...i did a clean install...and everything just works perfectly again...lightdm and all the rest install automatically along with the kernel upgrade to 4.8 series etc and everything just works again...hope this is of help to you and saves you some time...DAMIEN

Cosmo.
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Re: LightDM / MDM / Session problems after upgrading to 18.2

Post by Cosmo. » Wed Jul 05, 2017 6:45 pm

Can you log in into your account in a virtual machine? EDIT: sorry, typo: should read console. But you understood me.

How to:
Press ctrl-alt-F1
enter your username
enter your password. Note, that there is no visual feedback for the password, type it blindly, than press the Enter key.
Enter the command ls for a quick test. It should at least show you the directories in your home.

For getting out:
Press ctrl-d, than alt-left.
Last edited by Cosmo. on Thu Jul 06, 2017 5:51 am, edited 1 time in total.

blum
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Re: LightDM / MDM / Session problems after upgrading to 18.2

Post by blum » Thu Jul 06, 2017 4:15 am

[quote="Cosmo."]Can you log in into your account in a virtual machine?
Yes. That how I got back to MDM.

Cosmo.
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Re: LightDM / MDM / Session problems after upgrading to 18.2

Post by Cosmo. » Thu Jul 06, 2017 5:53 am

I am not sure, if you want to investigate further.

If so do the following:

At first create a fresh new user account.
Next replace once more mdm with lightdm.
Check if you can log in into the new account. (I assume so.)

blum
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Re: LightDM / MDM / Session problems after upgrading to 18.2

Post by blum » Thu Jul 06, 2017 12:42 pm

Everything works fine with a newly created user.

Deleted a lot of config dirs: .cinnamon, .gconf, .config, .dbus, .gnome, linuxmint, .local
So now I can log in. BUT The GUI is still very slow when I log into my acount. Works fine when I log into the newly create account.

All in all very annoying.
Maybe I should just do a clean install :(

Cosmo.
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Re: LightDM / MDM / Session problems after upgrading to 18.2

Post by Cosmo. » Thu Jul 06, 2017 5:16 pm

Your result shows, that the cause for your problem is not the system, but your account. So in the worst case using a new account will solve the problem.

But we can at first continue:
Go into the main account.
Mark the following command and press ctrl-c

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find $HOME ! -user $USER -type f
open a terminal and press ctrl-shift-V
Mark the complete result inclusive the command with the mouse and press ctrl-shift-C
In the forum click the Code-button above the text box, than press ctrl-v.

Report in case, that there is no output.

blum
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Re: LightDM / MDM / Session problems after upgrading to 18.2

Post by blum » Fri Jul 07, 2017 4:33 am

First of all thanks for putting in the time Cosmo.

Code: Select all

troels@nessa ~ $ find $HOME ! -user $USER -type f
find: ‘/home/troels/.cache/dconf’: Permission denied
troels@nessa ~ $ 
sudo ls -l /home/troels/.cache/dconf
[sudo] password for troels: 
total 4
-rw------- 1 root root 2 Jul  7 10:20 user
A bit strange because that wasn't there the first time i tried. Removed '/home/troels/.cache/dconf' still the problem is the same.


Looks like Xorg is using the vmware driver for my user for some reason. Really don't understand why I haven't installed vmware:
My user: glxgears

Code: Select all

GL_RENDERER   = Gallium 0.4 on llvmpipe (LLVM 3.8, 128 bits)
GL_VERSION    = 3.0 Mesa 12.0.6
GL_VENDOR     = VMware, Inc.
New user: glxgears

Code: Select all

GL_RENDERER   = Gallium 0.4 on AMD JUNIPER (DRM 2.49.0 / 4.10.0-26-generic, LLVM 3.8.0)
GL_VERSION    = 3.0 Mesa 12.0.6
GL_VENDOR     = X.Org
My user glxinfo

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Extended renderer info (GLX_MESA_query_renderer):
    Vendor: VMware, Inc. (0xffffffff)
    Device: llvmpipe (LLVM 3.8, 128 bits) (0xffffffff)
    Version: 12.0.6
    Accelerated: no
    Video memory: 7972MB
New user glxinfo:

Code: Select all

Extended renderer info (GLX_MESA_query_renderer):
    Vendor: X.Org (0x1002)
    Device: AMD JUNIPER (DRM 2.49.0 / 4.10.0-26-generic, LLVM 3.8.0) (0x68a1)
    Version: 12.0.6
    Accelerated: yes
    Video memory: 1024MB

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$ dpkg -la | grep vmware
ii  xserver-xorg-video-vmware                    1:13.1.0-2ubuntu3                            amd64        X.Org X server -- VMware display driver
$

Cosmo.
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Re: LightDM / MDM / Session problems after upgrading to 18.2

Post by Cosmo. » Fri Jul 07, 2017 5:42 am

At first: If there is no more in the output for the command I gave you except ~/.cache/dconf, than there is no ownership problem. This single object is the result of a bug, which exists since one year and persists now in the third Mint version. The only good new about it: It is harmless. And yes, if you remove this object, it will reappear. The cause is the update manager, more precisely its refresh mechanism.

But I see now, that your Mint is running in a virtual machine with VMW. I run here Mint 18.2 in VirtualBox and this gives no problem, inclusive using LightDM. But I have no experience with VMW, so I cannot help here.

blum
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Re: LightDM / MDM / Session problems after upgrading to 18.2

Post by blum » Fri Jul 07, 2017 5:52 am

But I am NOT running it in a virtual machine. At least not on purpose. I have NOT installed vmware.
This strange behavior only manifested after upgrading to 18.2

Cosmo.
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Re: LightDM / MDM / Session problems after upgrading to 18.2

Post by Cosmo. » Fri Jul 07, 2017 6:16 am

Hm, in this case I do not understand the output.

I let now the vmware output alone. As the test account works fine, it should be in any case an issue in the main account.

You wrote, that you deleted some folders; I assume, that you did this in the main account. What you deleted are indeed the most suspicious folders, but in your case the culprit is hidden somewhere else.

Go into the test account and copy all hidden files and folders from the main account over. (Leave .mozilla and .thunderbird, as they may be possibly very big and are definitely not the cause of the problem.) Log out and back into the test account. The problem should now appear there also. Now delete the hidden objects one by one (or in small groups), log after each deletion out and back in, until the problem is gone. This should encircle the culprit.

blum
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Re: LightDM / MDM / Session problems after upgrading to 18.2

Post by blum » Sat Jul 08, 2017 5:36 am

The problem is related to the account "troels" - my account - but not in my home dir.
What I did:

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cd /home
sudo rm -Rf troels
sudo cp -a /etc/skel troels
sudo chown -R troels:troels troels

And the problem still persists.

mgzArellano
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Re: LightDM / MDM / Session problems after upgrading to 18.2

Post by mgzArellano » Sat Apr 14, 2018 12:41 am

Hi,

I had exactly the same issue, I resolved this running the following command:

#dpkg-reconfigure lightdm

After I rebooted my computer and it worked pretty well.

Best,

smurphos
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Re: LightDM / MDM / Session problems after upgrading to 18.2

Post by smurphos » Sat Apr 14, 2018 2:07 am

blum wrote:
Fri Jul 07, 2017 4:33 am
Looks like Xorg is using the vmware driver for my user for some reason. Really don't understand why I haven't installed vmware:
My user: glxgears

Code: Select all

GL_RENDERER   = Gallium 0.4 on llvmpipe (LLVM 3.8, 128 bits)
GL_VERSION    = 3.0 Mesa 12.0.6
GL_VENDOR     = VMware, Inc.
That's the software rendering driver. It's likely you are logging in to the Cinnamon - Software Rendering session. Check on the MDM / LightDM login screen which session you are logging into to.

Correct procedure to replace MDM with lightDM (the blog post instructions are incomplete)

apt install slick-greeter lightdm lightdm-settings apparmor
chose lightDM as your display manager when asked
apt purge mdm
sudo dpkg-reconfigure lightdm
sudo reboot

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