From owner-freebsd-fs@FreeBSD.ORG Sun Feb 28 01:09:17 2010 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9FF9F106566C for ; Sun, 28 Feb 2010 01:09:17 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: from mail.garage.freebsd.pl (chello089077043238.chello.pl [89.77.43.238]) by mx1.freebsd.org (Postfix) with ESMTP id E1B4D8FC15 for ; Sun, 28 Feb 2010 01:09:15 +0000 (UTC) Received: by mail.garage.freebsd.pl (Postfix, from userid 65534) id 8371C45DD8; Sun, 28 Feb 2010 02:09:14 +0100 (CET) Received: from localhost (shell.garage.wheel.pl [10.0.4.3]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.garage.freebsd.pl (Postfix) with ESMTP id E609E45684; Sun, 28 Feb 2010 02:09:08 +0100 (CET) Date: Sun, 28 Feb 2010 02:09:06 +0100 From: Pawel Jakub Dawidek To: Dimitry Andric Message-ID: <20100228010906.GD2586@garage.freebsd.pl> References: <4B7FD4D2.7040802@andric.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="MPkR1dXiUZqK+927" Content-Disposition: inline In-Reply-To: <4B7FD4D2.7040802@andric.com> User-Agent: Mutt/1.4.2.3i X-PGP-Key-URL: http://people.freebsd.org/~pjd/pjd.asc X-OS: FreeBSD 9.0-CURRENT i386 X-Spam-Checker-Version: SpamAssassin 3.0.4 (2005-06-05) on mail.garage.freebsd.pl X-Spam-Level: X-Spam-Status: No, score=-5.9 required=4.5 tests=ALL_TRUSTED,BAYES_00 autolearn=ham version=3.0.4 Cc: freebsd-fs@freebsd.org Subject: Re: zfs on 4k sector disks X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 28 Feb 2010 01:09:17 -0000 --MPkR1dXiUZqK+927 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, Feb 20, 2010 at 01:25:54PM +0100, Dimitry Andric wrote: > On 2010-02-20 10:47, mailinglists wrote: > >This "Advanced Format" basically means the sectors size on disk is > >changed to 4k in stead of 512k. >=20 > Please note those disks still seem to expose 512B sectors to any OS; the > 4kiB sectors are only used internally. And there seems to be no jumper > to "fix" this behaviour... Unaligned writes can cause multiple > read-write-modify operations, which are most likely bad for performance. You can "fix" that with: # gnop create -S 4096 /dev/ad0 This command will create /dev/ad0.nop provider, which will expose 4kB sector (see diskinfo(8)). Unfortunately gnop won't survive reboot, as it doesn't use any metadata. --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --MPkR1dXiUZqK+927 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.14 (FreeBSD) iEYEARECAAYFAkuJwjEACgkQForvXbEpPzQ7SQCfbE40UkwzUdQtI6UwpcLKRxAE hjIAoJ+zRgrlQYIq23CUYy961nesw7+O =SN+L -----END PGP SIGNATURE----- --MPkR1dXiUZqK+927--