From owner-freebsd-current Thu Sep 26 12:59:59 2002 Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B2B8937B401 for ; Thu, 26 Sep 2002 12:59:58 -0700 (PDT) Received: from smart.eusc.inter.net (smart.eusc.inter.net [213.73.101.5]) by mx1.FreeBSD.org (Postfix) with ESMTP id 18B9543E75 for ; Thu, 26 Sep 2002 12:59:58 -0700 (PDT) (envelope-from msch@snafu.de) Received: from tc01-n70-041.de.inter.net ([213.73.70.41] helo=mscu.best-eng.de) by smart.eusc.inter.net with esmtp (Exim 3.36 #4) id 17uenf-0007lM-00 for freebsd-current@freebsd.org; Thu, 26 Sep 2002 21:59:52 +0200 Content-Type: text/plain; charset="us-ascii" From: Matthias Schuendehuette Reply-To: msch@snafu.de Organization: Micro$oft-free Zone To: freebsd-current@freebsd.org Subject: Re: Journaled filesystem in CURRENT Date: Thu, 26 Sep 2002 21:59:51 +0200 User-Agent: KMail/1.4.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-Id: <200209262159.51470.msch@snafu.de> Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Terry Lambert wrote: > Yes, soft updates does nothing of user data, it is a metadata > technology. Journalling is implementation dependent; not all > JFS implementations will journal data which is not metadata, so > your results would depend on the JFS. I think you are not correct here. If I understand Kirks paper right, Soft Updates do a sorting/nesting of data and metadata within the buffer cache. My knowledge is, that most of the journaling implementations do metadata journaling and do not guarantee data consistency (ext3 with data=journal is the only exception I know of), whereas SU *does* guarantee data consistency (admittedly with a time lag) because of that nesting from data with metadata. I'm far away from beeing able to follow this discussion in every detail, but please correct me if I'm wrong... -- Ciao/BSD - Matthias Matthias Schuendehuette , Berlin (Germany) Powered by FreeBSD 4.7-RC To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message