From owner-freebsd-geom@FreeBSD.ORG Thu Sep 29 07:46:48 2005 Return-Path: X-Original-To: freebsd-geom@freebsd.org Delivered-To: freebsd-geom@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C5D2916A41F for ; Thu, 29 Sep 2005 07:46:48 +0000 (GMT) (envelope-from lorenl@alzatex.com) Received: from hosea.tallye.com (joel.tallye.com [216.99.199.78]) by mx1.FreeBSD.org (Postfix) with ESMTP id 64BE143D48 for ; Thu, 29 Sep 2005 07:46:48 +0000 (GMT) (envelope-from lorenl@alzatex.com) Received: from hosea.tallye.com (hosea.tallye.com [127.0.0.1]) by hosea.tallye.com (8.12.8/8.12.10) with ESMTP id j8T7klGS008280 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Thu, 29 Sep 2005 00:46:47 -0700 Received: (from sttng359@localhost) by hosea.tallye.com (8.12.8/8.12.8/Submit) id j8T7kl5H008277 for freebsd-geom@freebsd.org; Thu, 29 Sep 2005 00:46:47 -0700 Date: Thu, 29 Sep 2005 00:46:47 -0700 From: "Loren M. Lang" To: freebsd-geom@freebsd.org Message-ID: <20050929074647.GA8081@alzatex.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="tThc/1wpZn/ma/RB" Content-Disposition: inline User-Agent: Mutt/1.4.1i X-GPG-Key: ftp://ftp.tallye.com/pub/lorenl_pubkey.asc X-GPG-Fingerprint: B3B9 D669 69C9 09EC 1BCD 835A FAF3 7A46 E4A3 280C X-Virus-Scanned: ClamAV version 0.87, clamav-milter version 0.87 on hosea.tallye.com X-Virus-Status: Clean Subject: How can soft-updates assume a certain write order? X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Sep 2005 07:46:48 -0000 --tThc/1wpZn/ma/RB Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable How does freebsd gaurentee that meta data is truely written out in the correct order to ensure data integrity? Does freebsd specifically wait for a response to come all the way from the disk drive itself before it schedules any dependent data to be written? And if so, is there any garuntee that any disk controllers, disk drives with their 16 meg caches, raid controllers or anything else won't change that order in an attempt to optimize? Or has the data truely been written to the disk by the time that the response comes back saying that the data's been written? --=20 I sense much NT in you. NT leads to Bluescreen. Bluescreen leads to downtime. Downtime leads to suffering. NT is the path to the darkside. Powerful Unix is. Public Key: ftp://ftp.tallye.com/pub/lorenl_pubkey.asc Fingerprint: CEE1 AAE2 F66C 59B5 34CA C415 6D35 E847 0118 A3D2 =20 --tThc/1wpZn/ma/RB Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQFDO5vnbTXoRwEYo9IRAn1nAJ4q2jx1OMTRmVGz+afLVoCihMYOIQCfchTn uVzupRzHaiSEgsKuRUcBg9U= =rMdd -----END PGP SIGNATURE----- --tThc/1wpZn/ma/RB--