12.04 no longer boots after apt-get upgrade

[SteveRiley]

1. Delete the file ~/.xsession-errors

2. Reboot

3. Try startx and watch it fail

4. Post copies of the files ~/.xsession-errors and /var/log/Xorg.0.log to http://pastebin.ubuntu.com and reply here with the URLs.


I have no experience with AMD graphics, but I might at least recognize some of the errors.

[Steve the Pocket]

Well, this is weird. I installed DiskInternals Linux Reader to look at the .xsesson-errors file from Windows before rebooting, and there was a sizable one there. But then after booting into a recovery mode shell, rm-ing the file, letting startx crash, and booting back into Windows, the file had not been recreated. And Xorg.0.log is just blank.

[SteveRiley]

I'm not sure if it's possible to start X from a recovery mode shell. I didn't realize that's what you were doing.

Try doing a normal boot, and allow it to fail. Then see if the system created those files I mentioned previously.

[Steve the Pocket]

Still no .xsession-errors, but we do have content in Xorg.0.log now. Here it is. I don't see anything that looks like an error, much less a crash.

[SteveRiley]

Weird. Would you please pastebin each file in /var/log/lightdm? You'll have to elevate to root to do this, as only root has read access to them.

[Steve the Pocket]

How would I go about submitting the files' contents to the site from within Linux? Or do I have to make duplicates with more lenient permissions and grabbing them from Linux Reader? (And if so, what's the simplest way to duplicate the whole folder and change the permissions of all its contents?)

[SteveRiley]

Perhaps that Linux Reader thing you're using in Windows? Have you checked whether it can see into the subdirectory I indicated?

[Steve the Pocket]

As it so happens, it can't even see the folder from within /var/log/.

[SteveRiley]

Ah, what am I thinking. You can get access to them if you boot into a recovery shell.

[Steve the Pocket]

Right. And then how do I get them onto the pastebin from there.

[vinnywright]

1- cd into /var/log/lightdm

vinny@vinny-HP-G62:~$ cd /var/log/lightdm

see what’s their

vinny@vinny-HP-G62:/var/log/lightdm$ ls
lightdm.log  x-0-greeter.log  x-0-greeter.log.old  x-0.log

make copy of file

vinny@vinny-HP-G62:/var/log/lightdm$ sudo cat lightdm.log > ~/lightdmlog.txt

you will have the file lightdmlog.txt in your home directory that you should have read Wright access to .

VINNY

[Snowhog]

Sorry Steve! I meant to delete my post, not yours.

If you don't have a directory called lightdm in /var/log/ then look for the files in /var/log
They will be:

drwxr-xr-x  2 root root 4096 Mar 31 07:01 .
drwxr-xr-x 14 root root 4096 Mar 31 07:23 ..
-rw-------  1 root root 3416 Mar 31 07:01 lightdm.log
-rw-------  1 root root  454 Mar 31 07:01 x-0-greeter.log
-rw-------  1 root root  454 Mar 30 18:51 x-0-greeter.log.old
-rw-------  1 root root 2219 Mar 31 07:01 x-0.log

[Steve the Pocket]

Turns out the reason I couldn't see the lightdm folder wasn't a permissons issue; the folder just plain wasn't there. Googling "lightdm" told me that it's the thing that controls the login screen, at least in vanilla Ubuntu, and how to launch it manually. Which I tried doing, out of curiosity, and...

The program 'lightdm' is currently not installed. You can install it by typing: apt-get install lightdm

Is it possible this is the problem? That it's one of the progtams that my little apt-get upgrade escapade wiped out? Or does Kubuntu not use it because KDE has its own login thing?

[Snowhog]

No, there is/was a 'problem' at some point in the fielding of lightdm, which removed kdm, which is actually required. So, give this a try:

sudo apt-get install kdm

This will install the kdm login manager.

[Steve the Pocket]

No, it says kdm's already installed and up-to-date. So that's not it.