Kubuntu freezes after logging in

[anuj kumar]

I have just installed Kubuntu since i loved KDE and I was pretty much used to ubuntu. I had been using Ubuntu(unity desktop) for about 2 years but hated the lack of options to customize things in it. SO I decided to switch to Kubuntu, where I was greeted with some issues. Initially, when I was trying to reduce the brightness of the screen using the function keys, it just used to go frozen with nothing working. I had to force turn off using the power key, which actually, was the only option I had at that time. Later on it was fixed as I found some setting which remembered the brightness setting, and I didn't need to change it on start-up anymore.

But this issue of "freezing" is still prevailing, as sometimes, and not every time, after showing the login screen, when I type in my password and hit enter, it goes FROZEN with nothing working, and I have to use the power key again. I am afraid, using this power key to turn off again again may ruin my hardware .
Someone please help.

[judedawson]

Hi Anuj,

Welcome to the wonderful world of Kubuntu, KDE and the solid Kubuntu Forums

I'm positive there's someone here who will be able to help you out.

First, we will need some essential info about your machine hardware & software.

Please read the post at this link:

http://www.kubuntuforums.net/showthr...W-GUY-lt-lt-lt

and update us with this info.

You'll get faster and precise tech support with this info.

Cheers.

From,
Jude

[anuj kumar]

Thanks a lot.
SO here are the details of my system:
Kubuntu release 12.10
KDE version 4.9.4
grub version 0.97-29ubuntu66
Windows 7 installed alongside.

Hardware description is as follows :
Type : Laptop
model : DELL n5010
CPU : core i3 (x86_64 architecture)
RAM : 4GB
HD : 500GB internal

[judedawson]

Hi Anuj,

Thanks for the info in Step#3.

Also, since you mentioned in Step#1 that this is a new install, perhaps you could also verify the source of the install (in ISO on CD, thumb-drive, etc.) checks out OK.

Just to be sure...appreciate if could confirm the MD5SUM of the ISO file is good.

See the below link for instructions:

https://help.ubuntu.com/community/HowToMD5SUM

Thanks.

From,
Jude

BTW - I, too, am 'rather new' to Kubuntu & do not know much tech support. I'm just helping out a fellow newbie

[Dutchman]

Hello anju, and welcome to Kubuntu Forums. There's two things I'd like for you to try, though the first may solve the problem if it's what I think it may be.

When you're in KDE, press ALT+F2 to bring up krunner, and type "session". You may not even get to type it all when you should see "Session Manager" as an option. Click on that to open the session manager settings. In the last group of options, "On Login", set it to "Start with an empty session". This will cause KDE to start up with a "default" session, so we can find out if there's something other than KDE trying to start and failing, causing the freeze. Click on "Apply" then "OK" to close the dialog. Log out and back in again, see if it still freezes. Being it's an intermittent problem you may have to do it many times to know if it's not going to freeze anymore.

Failing that, try creating another user. You can call it "test" or whatever you want, but create a new user account and log into it. It will be a bit of a pain because you won't have ready access to any of your regular user files, but if you can log in and out of the new user's account without any trouble, it gives us a clue on where to look next for the problem, narrows down the search.

Let us know how it goes.

Cheers,
Rob

[dmeyer]

Hello anju, and welcome to Kubuntu Forums. There's two things I'd like for you to try, though the first may solve the problem if it's what I think it may be.

When you're in KDE, press ALT+F2 to bring up krunner, and type "session". You may not even get to type it all when you should see "Session Manager" as an option. Click on that to open the session manager settings. In the last group of options, "On Login", set it to "Start with an empty session". This will cause KDE to start up with a "default" session, so we can find out if there's something other than KDE trying to start and failing, causing the freeze. Click on "Apply" then "OK" to close the dialog. Log out and back in again, see if it still freezes. Being it's an intermittent problem you may have to do it many times to know if it's not going to freeze anymore.

Failing that, try creating another user. You can call it "test" or whatever you want, but create a new user account and log into it. It will be a bit of a pain because you won't have ready access to any of your regular user files, but if you can log in and out of the new user's account without any trouble, it gives us a clue on where to look next for the problem, narrows down the search.

Let us know how it goes.

Cheers,
Rob

Good advice. Some KDE defaults seem great on paper but can sometimes cause serious issues. This is always one of the first things I do after a new install.

[anuj kumar]

Thanks Jade and Dutchman.

Recently, I found out that this problem of freezing, is not the matter of using function keys to change brightness or right after logging in after booting.

So far, from my experience from Kubuntu 12.10, I found it freezing in the following different situations :
1. when I tried changing brightness right after system start-up.
2. After logging on after system startup.
3. I left the system idle and went away for some time and found it frozen when I came back :P.
4. I left the system on sleep and when try to wake it up again, it froze with a black screen with a one-liner text, something like "usb0 not found" (don't remember exactly since it has happened only once).

I configured the session manager as suggested by Dutchman, still I faced the situation 3, though rest of them haven't happened so far after configuring.

Could anyone please suggest if there is a way to find out the program(s) which causes this conflict and leaves the system in such a state, by looking at the logs or something?

One more thing I wanted to ask is, are there any things that i can try to to recover or to reboot the system, before forcing shutdown using power key, as I said keyboard and mouse stop working. I tried the following and found them useless, ALT+CTRL+F1, ALT+CTRL+DEL, ALT+PRINT SCR.+R E I S U B.

[Teunis]

You mentioned the Magic Keys, R E I S U B
Did you do it this way:

ALT+PrtSc+R, wait a second,
ALT+PrtSc+E, wait a second,
etc

Now you mention this usb0 not found (or similar).
I've recently been playing with Linux installations on external drives and have seen such errors when a second USB drive was present during boot up, just yanking it made boot continue.

[Dutchman]

I second what Teunis wrote, and I'd add wait longer between attempts. Often when a Linux system "freezes" the kernel is trying to process something that's in a sense "keeping it's attention". It may take as much as 30 seconds or longer for the kernel to respond to your keystrokes, so when you try it, be patient. Give it a few minutes if you can between attempts, just to be sure.

Logs are often the best way to diagnose a problem. When there's a suspected hardware problem the first place I go is to 'dmesg'. This program shows everything the kernel has done while booting, and if there's a piece of hardware that's giving it problems often there will be some kind of indication there. The output from dmesg can be quite long, so to make it more convenient to read I suggest typing this in a terminal:

dmesg > ~/Desktop/dmesg.txt

That will create a plain text file in your Desktop folder with all the output from dmesg. You can then read through it, though admittedly most of what you'll see is beyond us mere mortals to understand. What you want to look for though is the kernel having trouble with something, usually worded like "could not load X, switching to Y" or "expecting X, found Y, switching to Z". While some of these kernel messages are normal and harmless, any that contain a recommendation to fix it are to be noted. Often when there's a problem the kernel will also make a suggestion on what to do about it.

Another place to check are the syslog, Xorg.0.log, udev, kern.log, and any other logs that may be relevant. You can find them in the '/var/log' directory. These files you should be able to just click on and open in your default text editor. Syslog and Xorg.0.log should definitely be checked.

One more thing I'd like to suggest anuj, that's doing a search here on Kubuntu Forums to see if anyone has had the same problem and already found the solution. You may want to use the advanced search feature to narrow your results, but there's a good chance your problem has already been solved by someone else here.