From owner-freebsd-stable@FreeBSD.ORG Wed Feb 22 00:50:30 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 5AC0516A420 for ; Wed, 22 Feb 2006 00:50:30 +0000 (GMT) (envelope-from illoai@gmail.com) Received: from xproxy.gmail.com (xproxy.gmail.com [66.249.82.198]) by mx1.FreeBSD.org (Postfix) with ESMTP id EF65443D49 for ; Wed, 22 Feb 2006 00:50:29 +0000 (GMT) (envelope-from illoai@gmail.com) Received: by xproxy.gmail.com with SMTP id t10so978892wxc for ; Tue, 21 Feb 2006 16:50:29 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=WrGqL8DdMfwpFQXFR8ABYYQ6sr2Rb03po7G02dum3FnV/i0FKEbKKJeLoBMwKcfLyEVxhc0KVV4Fy6r44j3rt15HIP9963zWkLbDMKQbUIikhQSSHCbew0588vQkVens9JfRF9yOWhTV60y//z13edk3Slsj4FhRwFeFrscECyQ= Received: by 10.70.51.19 with SMTP id y19mr5339034wxy; Tue, 21 Feb 2006 16:50:29 -0800 (PST) Received: by 10.70.58.15 with HTTP; Tue, 21 Feb 2006 16:50:29 -0800 (PST) Message-ID: Date: Tue, 21 Feb 2006 18:50:29 -0600 From: "illoai@gmail.com" To: "Eivind Olsen" , freebsd-stable@freebsd.org In-Reply-To: <20060221115027.GB60211@ip.net.ua> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline References: <43FAE446.4090807@aminor.no> <20060221115027.GB60211@ip.net.ua> Cc: Subject: Re: gmirror is confusing me, will I be bitten by the last-sector-use? 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: Wed, 22 Feb 2006 00:50:30 -0000 > > Now, how can I check whether my current partitions will cause trouble > > with the metadata-sector or not? I've done some searching on the net, > > but I'm still a bit confused. If I understand correctly, the consumers > > ad0/ad2 span 488397168 sectors (mediasize/sectorsize), and the > > mirror/gm0 spans 488397167 sectors. > > > In short: kernel (g_mirror) won't let you write to the last sector of its > media. > So long as your partition(s) exist(s) within the mirror device, you can't problem the metadata. If you tried writing to the last sectors of /dev/ad0 or /dev/ad2, you would damage or destroy the metadata. So, don't do that. I am curious about this case, does FreeBSD periodically check for the existance of the metadata, or (like some things, the kernel for instance) does it, once read and not rewritten, exist in memory, thus being able to be written over on disk, not to be noticed until reboot (or modification= , if such would be your wont)? -- --