From owner-freebsd-hackers Fri Feb 2 9:59: 0 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from fw.wintelcom.net (ns1.wintelcom.net [209.1.153.20]) by hub.freebsd.org (Postfix) with ESMTP id 8616E37B401 for ; Fri, 2 Feb 2001 09:58:40 -0800 (PST) Received: (from bright@localhost) by fw.wintelcom.net (8.10.0/8.10.0) id f12HwZC01055; Fri, 2 Feb 2001 09:58:35 -0800 (PST) Date: Fri, 2 Feb 2001 09:58:34 -0800 From: Alfred Perlstein To: Peter Wemm Cc: Lars Eggert , freebsd-hackers@FreeBSD.ORG Subject: Re: capturing an early kernel dump Message-ID: <20010202095834.Y26076@fw.wintelcom.net> References: <3A7A3180.35697C0E@isi.edu> <200102020739.f127dUW23005@mobile.wemm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <200102020739.f127dUW23005@mobile.wemm.org>; from peter@netplex.com.au on Thu, Feb 01, 2001 at 11:39:30PM -0800 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG * Peter Wemm [010201 23:40] wrote: > Lars Eggert wrote: > > > [Repost from last week, no answer then.] > > > > How do I capture an early kernel dump (before rc executes and sets > > dumpdev)? > > > > The dump partition used to be an option in the kernel config file, but that > > seems to have changed in 3.X or 4.X. > > > > Thanks, > > Lars > > How early? We could dump if you were prepared to hardwire in the minor and > major device numbers to get to the devsw[] vectors and manually set the > offsets. > > The biggest problem is that if it is Really Early (TM) we may not have read > the disk label and may not be able to see what the partitions look like. It > may need to be blindly dumped using a magic offset that you supply > somewhere and *hope* that you get the numbers correct so you dont trash > something. > > Alternatively.. dedicate a disk for it and just start dumping to the beginning > of the disk and work upwards... Well, doesn't the loader understand UFS? Why not have it pass the major/minor to the kernel? That way the loader can pass/set the dumpdev pretty safely by looking in /dev. -- -Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org] "I have the heart of a child; I keep it in a jar on my desk." To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message