Obtaining a kernel dump is not possible

[o***@snafu.de]

Hello,

my ThinkPad gets a kernel panic if I boot a kernel with atapicam
enabled. So I try to obtain a crash dump to get a backtrace.
Unfortunately it seems so, that the kernel crashs quit early. Although I
put dumpdev=/dev/ad0s1b in my loader.conf, I can't call doadump without
getting the message: "Partition too small. Dump failed."

I think, that the dumpdev hasn't been assigned at that specific moment
to the dumperinfo. Or is there another way to specify the dumpdev?

How can I all the same obtain a crash dump?

Regards,

Oliver Fischer

[o***@snafu.de]

Is your swap partition big enough ? It has to be at least as big as
your physical memory.

My swap is 1GB that is twice as much as my memory.

Regards,

Oliver Fischer

[t***@freebsd.org]

Post by o***@snafu.de
my ThinkPad gets a kernel panic if I boot a kernel with atapicam
enabled. So I try to obtain a crash dump to get a backtrace.

If dumping does not work, can you try to obtain a backtrace from DDB?

Thomas.

[p***@snafu.de]

Post by t***@freebsd.org
If dumping does not work, can you try to obtain a backtrace from DDB?

How can I get it and save it too?

Regards

Oliver Fischer

[t***@freebsd.org]

Post by p***@snafu.de
How can I get it and save it too?

First you need to configure your kernel with DDB, see:

http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/kerneldebug-online-ddb.html

and use the 'trace' command to obtain a backtrace once you get a panic.

I think the easiest way to save the trace is to obtain it from a serial
console, and save a transcript of the session on the terminal side.

Thomas.

[p***@snafu.de]

Post by t***@freebsd.org
I think the easiest way to save the trace is to obtain it from a serial
console, and save a transcript of the session on the terminal side.

Well, unfortunately my thinkpas doesn't have an serial port... :(

Regards,

Oliver Fischer

[t***@freebsd.org]

Post by p***@snafu.de
Well, unfortunately my thinkpas doesn't have an serial port... :(

Hmmm, OK. One kludgy solution I already saw used in such a case involves
a digital camera and taking a snap of the backtrace...

[j***@elischer.org]

Post by t***@freebsd.org

Post by p***@snafu.de
Well, unfortunately my thinkpas doesn't have an serial port... :(

does it have afirewire port?

Post by t***@freebsd.org
Hmmm, OK. One kludgy solution I already saw used in such a case involves
a digital camera and taking a snap of the backtrace...