From owner-freebsd-geom@FreeBSD.ORG Sat Jun 30 06:59:30 2007 Return-Path: X-Original-To: freebsd-geom@freebsd.org Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 4585916A468 for ; Sat, 30 Jun 2007 06:59:30 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: from mail.garage.freebsd.pl (arm132.internetdsl.tpnet.pl [83.17.198.132]) by mx1.freebsd.org (Postfix) with ESMTP id D13A213C4B8 for ; Sat, 30 Jun 2007 06:59:29 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: by mail.garage.freebsd.pl (Postfix, from userid 65534) id 0482F487F7; Sat, 30 Jun 2007 08:59:28 +0200 (CEST) Received: from localhost (cvl74.internetdsl.tpnet.pl [83.19.93.74]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.garage.freebsd.pl (Postfix) with ESMTP id F242345683; Sat, 30 Jun 2007 08:59:16 +0200 (CEST) Date: Sat, 30 Jun 2007 08:59:11 +0200 From: Pawel Jakub Dawidek To: Arne =?iso-8859-2?Q?W=F6rner?= Message-ID: <20070630065911.GB28006@garage.freebsd.pl> References: <20070629220604.GA28006@garage.freebsd.pl> <99891.46426.qm@web30301.mail.mud.yahoo.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="bCsyhTFzCvuiizWE" Content-Disposition: inline In-Reply-To: <99891.46426.qm@web30301.mail.mud.yahoo.com> X-PGP-Key-URL: http://people.freebsd.org/~pjd/pjd.asc X-OS: FreeBSD 7.0-CURRENT i386 User-Agent: mutt-ng/devel-r804 (FreeBSD) X-Spam-Checker-Version: SpamAssassin 3.0.4 (2005-06-05) on mail.garage.freebsd.pl X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=BAYES_00,RCVD_IN_NJABL_DUL autolearn=no version=3.0.4 Cc: Harry Newton , freebsd-geom@freebsd.org Subject: Re: gmirror on a slice uncertainty 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: Sat, 30 Jun 2007 06:59:30 -0000 --bCsyhTFzCvuiizWE Content-Type: text/plain; charset=iso-8859-2 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jun 29, 2007 at 10:52:36PM -0700, Arne W=F6rner wrote: > --- Pawel Jakub Dawidek wrote: > > On Fri, Jun 29, 2007 at 07:46:33AM -0700, Arne W=F6rner wrote: > > [...] > > > I wouldnt use a bsdlabel on the gmirror device > >=20 > > Why? It's perfectly safe and useful. > > > Because he wants to use the whole device for his "home" file system... > So he just introduces a 16 sectors offset... Both methods (mirroring entire disks and mirroring only slices/partitions) have pros and cons. Mirroring entire disks: - after a crash/power failure entire disk has to be synchronized, which may take a long time, + when one replaces disk, he doesn't have to configure slices/partitions on new disk, because everything will be synchronized, + after a crash/power failure there will be only one synchronization process running for the disks. Mirroring slices/partitions: + after crash/power failure only those partitions that were actively used will be synchronized (gmirror marks devices as clean where there are no writes in few seconds) - when one replaces disk, slices and partitions need to be configured by hand, and all partitions inserted to existing mirrors, - after a crash/power failure gmirror will synchronize all partitions at once which puts very heavy load on disks - this should be corrected in the future and currently may be worked around. + allows for fancy configurations - I've machine with five disks, that have two 'a' partitions mirrored for root, three 'a' partition in graid3 for /usr/ and five 'd' partitions in ZFS/RAIDZ for /usr/home/. I use both methods depending on my needs. --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --bCsyhTFzCvuiizWE Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (FreeBSD) iD8DBQFGhf8/ForvXbEpPzQRAug9AKCN5fb/xs9J6lT3X8UB0g5886NIsgCgq6t2 K4zg/DSGo/pSUuxEVuKFr+g= =d7tv -----END PGP SIGNATURE----- --bCsyhTFzCvuiizWE--