View Full Version : Linux machine crashing constantly

27-05-2012, 01:33 PM
Hey there

I have a Linux (Ubuntu) machine, and it has started locking up and crashing all the time, and I am not as familar with crash logs on Linux / Ubuntu as windows servers / machines - where is the best place to start?
Also when the mouse and keyboard freezes what is the same step to unlock it as CTRL ALT DEL?

Pardon the newbie questions..

Rod J
27-05-2012, 02:39 PM
Depends on which version of Ubuntu you are using. I've switched to Kubuntu (KDE desktop environment). I would look for System Log Viewer (or similar) in the System menu (from memory). Have a look at the syslog or kernel log for segfaults or other obvious crash reports. You can restart the X-windows system by using Ctrl-Alt-Backspace (I've used that before myself when a game or something stuffed the screen output). Ctrl-Alt-Delete usually logs you out. Another thing to try would be Ctrl-Alt-F1 (or F2 or F3, etc) which gives you a terminal/command line environment to use commands like top which allow you to kill misbehaving processes, etc. You can switch back to your still running gui environment by type Ctrl-Alt-F7 (usually F7 in (K)Ubuntu).

27-05-2012, 03:49 PM
Could be something with video drivers. Or a faulty hardware component (I had a hard drive once which was faulty and occasionally causing lock ups)
Logs are stored in /var/log, have a look around in there

27-05-2012, 06:47 PM
I guess it could be a lot of things - but one of the most likely in this situation is RAM - do you have 2 sticks with enough RAM on each to run one stick at a time and test?

Usually the <CTRL><ALT><BACKSPACE> is not enabled by default in Ubuntu. I am running Ubuntu 10.04 (GNOME) at the moment - see http://unixlab.blogspot.co.nz/2011/01/how-to-get-back-ctrl-alt-backspace-in.html but it may be different on a later version?

Rod J
27-05-2012, 11:20 PM
Usually the <CTRL><ALT><BACKSPACE> is not enabled by default in Ubuntu.

Yes, you're right John, I forgot it isn't set by default.

I'm running Kubuntu 12.04 now and it isn't set by default here either. The setting for it is in System Settings, Keyboard Settings, Advanced in Kubuntu 12.04. I still have Ubuntu 10.04 on another partition though.

28-05-2012, 01:54 AM
Did you recently install some new updates or did it just happen by itself?

I have not had Linux crash except due to driver issues or faulty hardware.

Run Memtest which should be listed in GRUB if you have Ubuntu, try removing\disabling other hardware especially 'interesting' devices like WiFi and TV Tuner cards

28-05-2012, 11:43 PM
All these answers are awesome, in the end I enabled better aircirculation (removed case lid) and it has been fine since so I am going to buy either bigger fans or a new case.

29-05-2012, 01:06 AM
I guess something was overheating then .. check for dust in your heatsinks\fans .. install a sensors program to monitor temperature perhaps.

29-05-2012, 11:31 AM
Yeah try installing "lm-sensors" to monitor your temperatures, then run "sensors-detect" to scan your system for all temperature sensors. For most Q's you can just hit Enter to use default answers :)
Then run 'sensors' to show the temperatures.

31-05-2012, 11:34 AM
I dusted it off, but I think the fans have been crappy for years, I think I am going to focus on the root cause, and replace them as well as the case, rather than the symptom :-)

The actual PC is ancient, but with Ubuntu it has run like a dream until I put it under the desk without as much airflow.

Protip: buy a crappy old PC for $200 and a $500 monitor - you will feel like you have a fast PC, it will almost never crash, and it looks amazing. It feels like a Mac under usual conditions, and it looks so pretty (cause that is important!) ;-)

31-05-2012, 12:06 PM
If it's 'ancient', check for bad capacitors in the motherboard, power supply and separate video card if you have one.

21-06-2012, 11:06 PM
Thanks agent_24 Its really poked now as I tool off the CPU fan to clean it with the air can and broke one of the mounting clip :-)

Ill get a new one and will be back to tricks again.

I'll also check the different components to see anything burn out though I think a new case or popping the current should make it work once I get it remounted! :-)

Thanks fo the friendly forum guys, really love all the ninja help. My hardware skills were never as good as my modem and networking skills. :-)

22-06-2012, 01:02 AM
Clip on the heatsink or the motherboard?