From owner-freebsd-hackers@FreeBSD.ORG Mon Sep 29 12:14:15 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 36FA316A4B3 for ; Mon, 29 Sep 2003 12:14:15 -0700 (PDT) Received: from mail.advantagecom.net (mail.advantagecom.net [65.103.151.155]) by mx1.FreeBSD.org (Postfix) with ESMTP id F01E743FF3 for ; Mon, 29 Sep 2003 12:14:13 -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 h8TJE9i17647; Mon, 29 Sep 2003 12:14:10 -0700 From: "Andrew Kinney" Organization: Advantagecom Networks, Inc. To: "Kang Liu" Date: Mon, 29 Sep 2003 12:14:50 -0700 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Message-ID: <3F78223A.9758.5C23391A@localhost> Priority: normal In-reply-to: <004901c3865c$37bf4120$e04e70ca@lkatschool> X-mailer: Pegasus Mail for Win32 (v3.12c) cc: freebsd-hackers@freebsd.org Subject: Re: Can not dump on raid dev? 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: Mon, 29 Sep 2003 19:14:15 -0000 On 29 Sep 2003, at 15:35, Kang Liu wrote: > Hi, > I'm trying to save a crashdump into /var/crash but it fails. > Here is my config files: > # dmesg | grep amr > amr0: mem 0xf0000000-0xf7ffffff irq 3 at device 0.0 on pci3 > amr0: Firmware 1.92, BIOS 3.31, 128MB RAM > amrd0: on amr0 > when the system crashes, it doesn't save any crashdump. > I've tried the same config on a machine with IDE disk, the crashdump can be saved. > Do I miss something, or the crashdump can not be saved on a raid device? > We had the same trouble with the mlx driver under 4.5, 4.7, and 4.8. The driver doesn't support crash dumps. I even tried making a ccd device since the driver code for ccd appears to support crash dumps. Didn't have any luck with that either. Ended up taking an old 4GB IDE hard drive and setting it up as a dedicated crash dump device. Just be sure you don't mount the swap partition you create on it because you don't want to compromise the benefits of having a RAID if you're using it for redundancy. The only other trick with that is that you have to have a BIOS that will allow you to define SCSI/RAID as your primary boot device. Some automatically assume you want to use IDE for boot if you have and IDE hard drive installed. If you're using RAID, you're probably also using a decent server board that includes the necessary boot options. If memory serves correctly, from what I read in the code, the only block device drivers that support crash dumps are IDE and some Adaptec SCSI cards. Don't know for sure about those Adaptec SCSI cards since we're not using one and you can't always trust what you see in the code about dumps as evidenced by the ccd driver. I believe it has something to do with it being necessary to use BIOS routines to write to the device since by the time you're doing a crash dump all your high level drivers are not useable anyway. Hope that helps. Sincerely, Andrew Kinney President and Chief Technology Officer Advantagecom Networks, Inc. http://www.advantagecom.net