Complete Lock Up, where to start?

I had something odd happen yesterday and its the second time its happened to me, I figured the first time was a fluke, both times it's occurred I was using Gnome shell. Basically the system completely freezes up no keyboard to touch pad no nothing, basically I end up having to force a power down and restart by holding down the power key.

Where do I begin to trouble shoot this issue, what log files should I take a peek at? I really don't even know where to begin with this one.

I feel I should mention this as it could be related every once in a while I'll get a blank screen, or my open windows will reload, again this only seems to happen while using Gnome shell. It's as if it gets confused as to what it supposed to be displaying but then quickly figures it out puts everything right.

Here is a list of the available log files:

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

You should start with systemlog, Xorg.0.log.

Ok I dug through the logs a bit but didn't find anything, I need a little more help on what to look for? I've been using unity lately and it's been flawless so I think the issue has something to do with gnome shell.

I doing a thread in desktop environments that seemed like a similar issue, without the screen blanking and window reloading. Their issue was solved by turning off "disable touch pad while typing", I'll give that a whirl tonight, but that is a feature I actually use so it's not really a great fix for me.

Any help with this is appreciated.

The "disable touchpad when typing" setting is not as bad as you think - you can still use the touch pad - it just stops you inadvertantly "tap clicking" or "cursor moving" while you are actually typing on the keyboard. Stop typing for a second (well less than that), and you can use the touchpad.

I wonder if the package "lightdm" is giving you trouble.

https://wiki.ubuntu.com/LightDM

Quote:

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Originally Posted by Tony Flury

The "disable touchpad when typing" setting is not as bad as you think - you can still use the touch pad - it just stops you inadvertantly "tap clicking" or "cursor moving" while you are actually typing on the keyboard. Stop typing for a second (well less than that), and you can use the touchpad.

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Sorry I may not have explained myself right. I'm a chronic tap clicker/courser mover so I need to use the disable touchpad. The other thread suggested disabling it as a fix to a similar issue.

Quote:

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Originally Posted by jerrrys

I wonder if the package "lightdm" is giving you trouble.

https://wiki.ubuntu.com/LightDM

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So how can or should I trouble shoot it? I read the wiki but there's no info on common issues. I could switch back to gdm but what issues will that cause.

Being a rather random problem makes it hard to track down.

You might try the skinny elephant trick. It is a way to regain control of a frozen system.

look at step 5 of this post:
http://lxtips.posterous.com/recover-...ystem-with-alt


Sometimes you can also get to a virtual terminal by pressing ctrl-alt-F1 and then using ps or top to kill the offending process(es), and then pressing ctrl-alt-F7 to get back to your desktop. maybe this trick will let you see what process is causing the problem.

Are any of the lights flashing on the machine? This usually indicates "kernel panic". The most common cause I've seen with Linux is graphics driver issues. try turning of the desktop effects.
Also if you can do: Ctrl+Alt+F1
and it drops to tty1 then that means X is crashing (also gpu related) not kernel panic.
What is the make and model??

Quote:

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Originally Posted by bronquel

You might try the skinny elephant trick. It is a way to regain control of a frozen system.

look at step 5 of this post:
http://lxtips.posterous.com/recover-...ystem-with-alt


Sometimes you can also get to a virtual terminal by pressing ctrl-alt-F1 and then using ps or top to kill the offending process(es), and then pressing ctrl-alt-F7 to get back to your desktop. maybe this trick will let you see what process is causing the problem.

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I wish I would have seen this a while ago, I was having this issue recurring on a old load of Ubuntu 11.10. Eventually I have had to reload (due to other reasons) and it has not resurfaced yet. This will be very useful if I run into it again.