freezing problems

[Matt Patterson]

Okay, so I will try and disseminate what I have learned in my search of 
a stable machine (which I finally have :)).

So the first thing to do is google search for "your motherboard linux 
freeze" or "your motherboard linux hang". Do that for your video card, 
network card, etc, mixing and matching what items are in the search. You 
may well find out that your problem is common and there is a simple 
solution like a patch, different kernel to use, or a bios update.

Now the generic troubleshooting guide:

The quick fixes are disabling the apic and local apic. The apic is the 
advanced interupt controller which is supposedly an improvement over the 
standard interrupt controller which has been with us since the early 
days of computers. Unfortunately some just dont work or dont like linux. 
If I remember right the loapic (local apic) only applies to 
multiprocessor machines, it is just an exension to an apic which 
distributes interrupts between the processors. Either way, disable both 
of them by passing them as kernel options during boot. The easiest way 
to do that is to press ESC at the GRUB screen when it prompts for you to 
do so (I think it is ESC). Then edit the default kernel boot line adding 
noapic and nolapic to the end. These changes are not permanent, only for 
the current boot. To change them permanently you have to add them to the 
/boot/grub/menu.lst file options.

Another option to add the the kernel options is acpi=off or noacpi (i 
cant remember which, so just do both). This turns off  the acpi features 
of the kernel. Acpi is used to enumerate the interrupts on the system, 
but some bioses just suck and dont work, so turn off the features for 
now. This might cause some things to disappear and stop working on 
laptops, but its a good test. It will also prevent power saving features 
from working.

Turn off all the graphics acceleration features in your 
/etc/X11/xorg.conf file. That means commenting out the dri, and glx 
lines. Also, if binary drivers are available for your graphics card, try 
using the open sourced and binary to see which is more stable. An 
additional trick for nvidia owners is the agp option. Disabling use of 
agp can be helpful (only for binary drivers). Option      "NvAGP"     
"0".  There are items on www.ubuntuguide.org to tell you how to 
install/uninstall the binary drivers.

In desperation its time to move to hardware options. Start by turning 
all memory timings as slow as possible (BIOS). Remove all but one memory 
dimm and try different slots. Remove the sound, network, and scsi cards 
looking for one that fixes your problem. Also try moving the cards to 
different slots. Maybe also try a different video card. You should run 
the memtest boot option (available from the GRUB menu at bootup).

The very very final changes are the power supply, cpu cooler, and 
motherboard. Poor power supplies can have surprising repurcussions on 
system stability.

If none of that works, perhaps you should go back to winows, hehehe. I'm 
gonna get flamed for that comment!

Matt



Charles Malespin wrote:

>On Tue, 2005-06-14 at 15:17 -0400, Matt Patterson wrote:
>  
>
>>Generally hard freezes are hardware issues related to interrupt 
>>problems. So I would look into disabling devices like network and sound 
>>and see if the problem continues. Also, of course try the acpi=off, 
>>noapic, nolapic options for the kernel.
>>    
>>
>
>Hi Matt, I am having this problem as well, I am using the ATI X300 video
>card fyi.  I am still very much a noob in linux and ubuntu so could you
>please describe what turning acpi=off and noapic will do, and perhaps
>how to do it?  The freezes happen sometimes after 30 min of a fresh
>boot, maybe 20 hours.  No pattern or real cause and I have NO idea where
>to troubleshoot or look for solutions.  Thanks!
>Charles
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