[opensuse-kernel] How do I debug a kernel panic?
Hi, I occasionally get a kernel panic, at least I assume it is because everything freezes except for blinking keyboard lights, when compiling with multiple jobs using scons but I can't find anything in the log to indicate where it happened. I'm already running kdump but it doesn't trigger. I think I can reproduce the panic with a particular resource hungry compile so what can I do to debug this problem? Regards Dave P -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
On Thu, 11 Feb 2010 13:08:58 +0200 Dave Plater wrote:
Hi, I occasionally get a kernel panic, at least I assume it is because everything freezes except for blinking keyboard lights,
That indeed looks like a kernel panic.
when compiling with multiple jobs using scons but I can't find anything in the log to indicate where it happened. I'm already running kdump but it doesn't trigger. I think I can reproduce the panic with a particular resource hungry compile so what can I do to debug this problem?
See http://en.opensuse.org/Bugs/Kernel for the introduction to kernel debugging (especially the chapters "Capturing Oops info" and "Using the serial console" might be interesting to you). If you need X to reproduce the bug and the machine does not have a serial port (which is too common these days, unfortunately), you can try to use netconsole - see a short howto in https://bugzilla.novell.com/show_bug.cgi?id=444149#c43 Thanks, Jiri -- Jiri Benc SUSE Labs -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
Hi Dave, Le jeudi 11 février 2010 12:08, Dave Plater a écrit :
Hi, I occasionally get a kernel panic, at least I assume it is because everything freezes except for blinking keyboard lights, when compiling with multiple jobs using scons but I can't find anything in the log to indicate where it happened. I'm already running kdump but it doesn't trigger. I think I can reproduce the panic with a particular resource hungry compile so what can I do to debug this problem?
Have the console visible (Ctrl+Alt+F1) when the panic happens and you should see a backtrace. An alternative is setting up a serial console. -- Jean Delvare Suse L3 -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
On 02/11/2010 05:44 AM, Jean Delvare wrote:
Hi Dave,
Le jeudi 11 février 2010 12:08, Dave Plater a écrit :
Hi, I occasionally get a kernel panic, at least I assume it is because everything freezes except for blinking keyboard lights, when compiling with multiple jobs using scons but I can't find anything in the log to indicate where it happened. I'm already running kdump but it doesn't trigger. I think I can reproduce the panic with a particular resource hungry compile so what can I do to debug this problem?
Have the console visible (Ctrl+Alt+F1) when the panic happens and you should see a backtrace.
An alternative is setting up a serial console.
The logging console (Ctrl+Alt+F10) is usually a bit more instructive. You will have to write down the contents or take a photo, and part of the message will usually scroll off the screen, but it is generally enough to get some clues. Larry -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
Le jeudi 11 février 2010 17:51, Larry Finger a écrit :
On 02/11/2010 05:44 AM, Jean Delvare wrote:
Hi Dave,
Le jeudi 11 février 2010 12:08, Dave Plater a écrit :
Hi, I occasionally get a kernel panic, at least I assume it is because everything freezes except for blinking keyboard lights, when compiling with multiple jobs using scons but I can't find anything in the log to indicate where it happened. I'm already running kdump but it doesn't trigger. I think I can reproduce the panic with a particular resource hungry compile so what can I do to debug this problem?
Have the console visible (Ctrl+Alt+F1) when the panic happens and you should see a backtrace.
An alternative is setting up a serial console.
The logging console (Ctrl+Alt+F10) is usually a bit more instructive. You will have to write down the contents or take a photo, and part of the message will usually scroll off the screen, but it is generally enough to get some clues.
Would you believe that? You just tought me about the logging console, I didn't know about it! That being said, in my experience panic messages are printed to whatever console is active so it shouldn't actually matter... cool feature for other cases though! -- Jean Delvare Suse L3 -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
Hi, Am 11.02.2010 12:08, schrieb Dave Plater:
Hi, I occasionally get a kernel panic, at least I assume it is because everything freezes except for blinking keyboard lights, when compiling with multiple jobs using scons but I can't find anything in the log to indicate where it happened. I'm already running kdump but it doesn't trigger. I think I can reproduce the panic with a particular resource hungry compile so what can I do to debug this problem?
Have you considered to setup kdump? With openSUSE, that's really easy: Just fire up YaST and choose the kdump module. You may have to install the "yast2-kdump" package before. After the setup is complete, reboot. If the crash happens, a dump file is written to the disk. You might not see any output on the console, just watch the disk activity (or setup a serial console). After that, a dump is in /var/crash. That dump can be opened with crash(1). See http://en.opensuse.org/Kdump and http://en.opensuse.org/Crashdump_Debugging. HTH, Bernhard -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
participants (5)
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Bernhard Walle -
Dave Plater -
Jean Delvare -
Jiri Benc -
Larry Finger