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To: Robert Watson <rwatson@FreeBSD.org>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Tue, 20 Jan 2004 22:19:02 EST."
             <Pine.NEB.3.96L.1040120221452.53972J-100000@fledge.watson.org> 
Date: Wed, 21 Jan 2004 07:25:26 +0100
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cc: wpaul@FreeBSD.org
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cc: bde@zeta.org.au
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cc: Don Lewis <truckman@FreeBSD.org>
cc: cvs-all@FreeBSD.org
Subject: Re: cvs commit: src/sys/alpha/alpha support.s src/sys/i386/i386
	swtch.s src/sys/kern kern_shutdown.c src/sys/sys systm.h 
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In message <Pine.NEB.3.96L.1040120221452.53972J-100000@fledge.watson.org>, Robe
rt Watson writes:
>
>On Tue, 20 Jan 2004, Don Lewis wrote:
>
>> It would be extremely helpful to preserve the panic message and
>> (optionally) the backtrace across the reboot.  Crash dumps may not
>> always be possible for any number of reasons (swap smaller than RAM,
>> /var/crash too small or overflowing with previous crash dumps, crash
>> dump takes too long ...).  This is especially true in cases where the
>> machine crashes and reboots unattended. 
>
>Actually, I was having a very similar conversation with Bill Paul this
>afternoon.  We were discussing dropping a copy of the kernel message
>buffer onto the header of swap space on panic

Just remember to stay out of the first 16kb so you don't trash
bootblocks/disklabels should they live there.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.