From owner-freebsd-stable@FreeBSD.ORG Thu Jan 19 12:24:54 2006 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DCB3A16A41F for ; Thu, 19 Jan 2006 12:24:54 +0000 (GMT) (envelope-from ler@lerctr.org) Received: from lerami.lerctr.org (lerami.lerctr.org [192.147.25.11]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7A61043D45 for ; Thu, 19 Jan 2006 12:24:54 +0000 (GMT) (envelope-from ler@lerctr.org) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=lerami; d=lerctr.org; b=mZn4pOA+DtNdXHVYiXNyzdMHwCTjUHai5+x7e5iJ9StXTKa/XcXHTOot/bcIR2QIXGw/wQtEn8Ef5XVRbu7ivBCdHnidtDqw2APOkdFwoqWY7NoBsU3o4QiNToe2Gyl7mwdJrxaA3VgfixRczjOehOGqi08cELmJQoHEDYQfSZI=; Received: from ppp-70-129-200-204.dsl.austtx.swbell.net ([70.129.200.204]:2853 helo=lerlaptop) by lerami.lerctr.org with esmtpsa (TLSv1:RC4-MD5:128) (Exim 4.60) (envelope-from ) id 1EzYqR-0005nS-8H; Thu, 19 Jan 2006 06:24:54 -0600 From: "Larry Rosenman" To: "'Gavin Atkinson'" Date: Thu, 19 Jan 2006 06:24:50 -0600 Message-ID: <00c401c61cf3$581cc930$68c8a8c0@lerctr.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 11 In-Reply-To: <1137672877.89997.8.camel@buffy.york.ac.uk> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2670 Thread-Index: AcYc8fIIG/6PTGtkRSWoisGKuDy02AAATmIw X-Spam-Score: -4.4 (----) X-LERCTR-Spam-Score: -4.4 (----) X-Spam-Report: (-4.4 points, 5.0 required) ALL_TRUSTED=-1.8 BAYES_00=-2.599 DK_POLICY_SIGNSOME=0.001 X-LERCTR-Spam-Report: (-4.4 points, 5.0 required) ALL_TRUSTED=-1.8 BAYES_00=-2.599 DK_POLICY_SIGNSOME=0.001 DomainKey-Status: no signature Cc: freebsd-stable@freebsd.org Subject: RE: Gmirror'd SWAP: no dump? 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: Thu, 19 Jan 2006 12:24:55 -0000 Gavin Atkinson wrote: > On Thu, 2006-01-19 at 05:49 -0600, Larry Rosenman wrote: >> Igor Robul wrote: >>> On Wed, Jan 18, 2006 at 12:44:27PM -0600, Larry Rosenman wrote: >>>> Are there any plans to support dumping to a gmirror'd swapfile? >>> Dumping occurs when kernel is in "bad condition", so GEOM can not be >>> safe used (for example panic in GEOM code). >>> >>> Check archives for last month of 2005 for longer explanation. >> >> I was afraid of that. What's the recommendation for how to Set up a >> 2-disk system with mirroring then? >> >> All the HOWTO's I've seen have the entire disk mirrored, including >> all the pieces. >> >> My current setup is 3 BSD partitions in 1 FDISK slice. With the >> entire disk (da0/da1) mirrored. >> >> How can I set it up to allow dumps? > > If you look at the mirror status, you'll see each disk is assigned a > priority. > > In theory, "The component with the biggest priority is used [...] as > a master component when resynchronization is needed, e.g. after a > power failure when the device was open for writing." (gmirror(8)). > Therefore, if you set dumps to /dev/da0s1b (or whichever swap > partition is on the disk with the biggest priority), the machine can > dump to the disk directly, and will end up resyncing to the other > disk on reboot (which it would have had to do anyway due to the > panic), and your dump will be doubly safe. The problem with this idea is the fact that the da0s1b device is NOT available: $ ls -l /dev/da?s1? ls: /dev/da?s1?: No such file or directory $ -- Larry Rosenman http://www.lerctr.org/~ler Phone: +1 512-248-2683 E-Mail: ler@lerctr.org US Mail: 430 Valona Loop, Round Rock, TX 78681-3683 US