Re: obtaining a kernel crash dump

From: Peter Pentchev (roam_at_ringlet.net)
Date: 05/19/04

  • Next message: Pawel Jakub Dawidek: "Re: api for sharing memory from kernel to userspace?" 
    Date: Wed, 19 May 2004 17:20:04 +0300
To: Nick Strebkov <nick@humgat.org>

    On Wed, May 19, 2004 at 04:34:42PM +0300, Nick Strebkov wrote:
    > Hi there.
    >
    > I can't obtain a crash dump.
    >
    > % cat /sys/i386/conf/DEVEL | grep makeoptions
    > makeoptions DEBUG=-g
    > % cat /etc/rc.conf| grep dump
    > dumpdev="/dev/ar0s1b"
    > dumpdir="/var/crash"
    >
    > I'm testing my kernel patch and the following is what I see in
    > /var/log/messages:

    Can you force the kernel to dump by using DDB? Place 'options DDB' in
    your kernel config, then, when the system is quiescent, hit Ctrl-Alt-Esc
    and type 'panic' at the DDB prompt.

    If this works, and you get a crash dump, then the problem might be that
    with your kernel patch, the kernel is panicking in a low-level layer,
    like memory management or disk drivers or something like that, and it
    simply cannot make a crash dump, since that would mean invoking code
    that depends on bad data or something.

    G'luck,
    Peter 

    -- 
Peter Pentchev	roam@ringlet.net    roam@sbnd.net    roam@FreeBSD.org
PGP key:	http://people.FreeBSD.org/~roam/roam.key.asc
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Hey, out there - is it *you* reading me, or is it someone else?

  • Next message: Pawel Jakub Dawidek: "Re: api for sharing memory from kernel to userspace?"

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