From owner-freebsd-hackers@FreeBSD.ORG Fri Apr 25 08:39:57 2003 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C6F8337B401 for ; Fri, 25 Apr 2003 08:39:57 -0700 (PDT) Received: from mail.advantagecom.net (mail.advantagecom.net [65.103.151.155]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0D5D543FCB for ; Fri, 25 Apr 2003 08:39:57 -0700 (PDT) (envelope-from andykinney@advantagecom.net) Received: from SCSI-MONSTER (scsi-monster.advantagecom.net [207.109.186.200]) by mail.advantagecom.net (8.11.6/8.11.6) with ESMTP id h3PFduF08458 for ; Fri, 25 Apr 2003 08:39:56 -0700 From: "Andrew Kinney" Organization: Advantagecom Networks, Inc. To: freebsd-hackers@freebsd.org Date: Fri, 25 Apr 2003 08:39:12 -0700 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Message-ID: <3EA8F430.11277.77B4EF97@localhost> Priority: normal In-reply-to: <3EA6522A.25198.6D6A8B3D@localhost> X-mailer: Pegasus Mail for Win32 (v3.12c) Subject: Re: dump routine for mlx devices X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: andykinney@advantagecom.net List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 25 Apr 2003 15:39:58 -0000 On 23 Apr 2003, at 8:43, Andrew Kinney wrote: > That last one (ccd) could be a point of interest. Is it possible to > create a ccd device from a spare mlxd device? If so, is it also > feasible to swap and dump to that ccd device or would it fail because > the "real" device didn't support dumps? Footnote: I decided to try it and here are the results, but you probably all knew this already. dumping to dev #ccd/0, offset 9372672 dump failed, reason: device bad Of course, this begs the question, why does the ccd driver code indicate it supports crash dumps? Looks like I'm just going to have to break down and install an IDE disk to get those crash dumps I need, unless someone wants to address this part of my question: > dumping to dev #mlxd/0x20001, offset 9372672 > dump failed, reason: device doesn't support a dump routine > > Before I go try to write my own dump routine: Has anyone else > already invented that wheel or is the wheel too difficult a pursuit in > this case due to peculiarities of this hardware? I'd be willing to write the dump routine and pass it to the code maintainer for that driver, but I'd like to know if anyone has tried it before and run into a show-stopper. It would valuable for the FreeBSD community at large to be able to use a mlx RAID for a crash dump, though some of us value it more than others. The obvious problem with using an IDE hard drive for crash dumps is that it represents a single point of failure that could bring the system down if the disk went bad while it was included in the swap space. Sincerely, Andrew Kinney President and Chief Technology Officer Advantagecom Networks, Inc. http://www.advantagecom.net