From owner-freebsd-arch@FreeBSD.ORG Tue Nov 4 17:57:12 2003 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 96F2016A4D7 for ; Tue, 4 Nov 2003 17:57:11 -0800 (PST) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by mx1.FreeBSD.org (Postfix) with ESMTP id DA01743FD7 for ; Tue, 4 Nov 2003 17:57:10 -0800 (PST) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.12.9/8.12.9) id hA51vA23002956; Tue, 4 Nov 2003 19:57:10 -0600 (CST) (envelope-from dan) Date: Tue, 4 Nov 2003 19:57:10 -0600 From: Dan Nelson To: Wes Peters Message-ID: <20031105015709.GC28915@dan.emsphone.com> References: <200311041737.20467.wes@softweyr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200311041737.20467.wes@softweyr.com> X-OS: FreeBSD 5.1-CURRENT X-message-flag: Outlook Error User-Agent: Mutt/1.5.4i cc: arch@freebsd.org Subject: Re: newfs and mount vs. half-baked disks X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 05 Nov 2003 01:57:12 -0000 In the last episode (Nov 04), Wes Peters said: > I emailed Kirk about this state of affairs and he confirmed that > newfs was developed with operator intervention in mind. He suggested > employing one of the unused flags in the filesystem header as a > 'consistent' flag, setting it to 'not consistent' at the beginning of > newfs, and then updating to 'is consistent' at the end. The > performance hit in updating all superblock copies at the end is small > but noticable (< 1s on a rather slow 6GB filesystem). Would writing a block of zeros to the first (or first n) superblock, newfs'ing, then rewriting the correct data do the same thing without affecting the filesystem itself? I'm thinking about 4.x and cross-OS portability here. -- Dan Nelson dnelson@allantgroup.com