From owner-freebsd-questions@FreeBSD.ORG Tue Oct 28 17:25:16 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 7694C106566B for ; Tue, 28 Oct 2008 17:25:16 +0000 (UTC) (envelope-from stefan.moro@gmail.com) Received: from wa-out-1112.google.com (wa-out-1112.google.com [209.85.146.183]) by mx1.freebsd.org (Postfix) with ESMTP id 4F7A38FC28 for ; Tue, 28 Oct 2008 17:25:16 +0000 (UTC) (envelope-from stefan.moro@gmail.com) Received: by wa-out-1112.google.com with SMTP id n4so1515108wag.27 for ; Tue, 28 Oct 2008 10:25:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:mime-version:content-type:content-transfer-encoding :content-disposition; bh=2qgORhfeEP5mPlW/pRNVRAlcCf3YvZPTHuj96bsY8vQ=; b=szmljDeyywefxoybY7uNfmZcFi2THrsIOG9leTRRX6dziK1tWOBQIZ60/nvW1d07pT 7WaWE8ut4l6wAkMkBuUmUNBuCg4nIrj0qGNWp97gHxI7MArWhnMWdeP1j6YZH4kQ9HIa 5VIAuNaclqGuYOnMorBZ99D3zo1J5hdZNJ6us= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:mime-version:content-type :content-transfer-encoding:content-disposition; b=wWUOhWrVxcZyebIq3Sy+L5Dl8RJ5MIl0g+jAkxOVKc3OywDjILy5IY+INw5h11sIF2 huZeQv4X5G0XqCbuu/hzGyfWdxsgZXuWeZI0CXZU27kUBYsfKWtWj+FBI3PTFreadG85 P03Q1mFcb9guKrrytq3NXXx+3vWhDbsrYXi2E= Received: by 10.114.73.1 with SMTP id v1mr6348041waa.110.1225212800554; Tue, 28 Oct 2008 09:53:20 -0700 (PDT) Received: by 10.114.160.6 with HTTP; Tue, 28 Oct 2008 09:53:20 -0700 (PDT) Message-ID: <2961fef0810280953g48b5ea28y8aebf58bd8e8afb7@mail.gmail.com> Date: Tue, 28 Oct 2008 17:53:20 +0100 From: "Stefan Moro" To: freebsd-questions@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Subject: A gmirror question. X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Oct 2008 17:25:16 -0000 Hi! I've got a question regarding the way that gmirror identifies what "components" (if that is the right term) are included in a mirror. I recently created a mirror over two disks, ad2 and ad4. After some bios changes (activating PATA) these devices were changed to ad6 and ad10 respectively. The "magic" thing (which probably isn't so magic =) ) here is that after reboot, gmirror still managed to identify the mirror, now using ad6 and ad10. If I have understood things correctly, gmirror stores all relevant information about the mirror in the last sector on the provider. So I guess one possible solution is that gmirror ,during startup, scans all disks/slices for this magic sector and then "starts" the mirror. But if this is the case, how does gmirror know that it should use (in my example above) ad10 and not ad4 as the additional disk in the mirror. Or does gmirror use something else than the /dev entries to address disks?? I'm just curious how gmirror does this. BR Stefan