From owner-freebsd-stable@FreeBSD.ORG Fri Aug 6 23:04:20 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id AB87F106566C for ; Fri, 6 Aug 2010 23:04:20 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from qmta12.westchester.pa.mail.comcast.net (qmta12.westchester.pa.mail.comcast.net [76.96.59.227]) by mx1.freebsd.org (Postfix) with ESMTP id 5927F8FC08 for ; Fri, 6 Aug 2010 23:04:19 +0000 (UTC) Received: from omta15.westchester.pa.mail.comcast.net ([76.96.62.87]) by qmta12.westchester.pa.mail.comcast.net with comcast id qzHW1e0021swQuc5CB4Lf2; Fri, 06 Aug 2010 23:04:20 +0000 Received: from koitsu.dyndns.org ([98.248.41.155]) by omta15.westchester.pa.mail.comcast.net with comcast id rB4K1e00R3LrwQ23bB4L9f; Fri, 06 Aug 2010 23:04:20 +0000 Received: by icarus.home.lan (Postfix, from userid 1000) id 184E49B423; Fri, 6 Aug 2010 16:04:18 -0700 (PDT) Date: Fri, 6 Aug 2010 16:04:18 -0700 From: Jeremy Chadwick To: Mark Saad Message-ID: <20100806230418.GA51617@icarus.home.lan> References: <201008062231.o76MVEji063809@lurza.secnetix.de> <915273.79945.qm@web35301.mail.mud.yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <915273.79945.qm@web35301.mail.mud.yahoo.com> User-Agent: Mutt/1.5.20 (2009-06-14) Cc: freebsd-stable@FreeBSD.ORG Subject: Re: Dumpdev issue in 6.4-STABLE X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 06 Aug 2010 23:04:20 -0000 On Fri, Aug 06, 2010 at 03:37:37PM -0700, Mark Saad wrote: > > Mark Saad wrote: > > > > wrote: > > > > > I then set in /boot/loader.conf > > > > > > > > > > dumpdev="/dev/da0s1b" > > > > > > > > On 8-STABLE dumpdev should be defined in rc.conf(5).  > > > > Not sure about > > > > 6-STABLE offhand. > > > > > > The box dies before init is started so dumpdev in > > rc.conf is pointless. > > > > I'm afraid you can't set dumpdev from the loader. > > > > In ancient times it was possible to hardcode the dumpdev > > via the kernel configuration, but that option is long > > gone, AFAIK. > > > Oliver so how do I get a core file of what the kernel is doing ? What is the "new way" of doing this ? Use of dumpdev in /etc/rc.conf is utilised by /etc/rc.d/dumpon. This rc script runs /sbin/dumpon, specifying the device, which tells the kernel what device to dump stuff to using an ioctl() call for DIOCSKERNELDUMP. There doesn't appear to be a way to make an ioctl call from within DDB. I would say you're basically out of luck; someone on freebsd-hackers may know of a secret way. Otherwise I would say DDB needs to be extended to provide a "dumpdev" command or something along those lines which would do the ioctl() equivalent. You can drop to DDB interactively by pressing Control-Alt-Escape. You can examine the system state from there, but even "call doadump" probably won't work given that the kernel doesn't know what dump device to use (re: the ioctl() call above). -- | Jeremy Chadwick jdc@parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |