From owner-freebsd-fs@FreeBSD.ORG Sat Oct 23 08:59:13 2010 Return-Path: Delivered-To: fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 14B8C106564A for ; Sat, 23 Oct 2010 08:59:13 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: from mail.garage.freebsd.pl (60.wheelsystems.com [83.12.187.60]) by mx1.freebsd.org (Postfix) with ESMTP id B22418FC0C for ; Sat, 23 Oct 2010 08:59:12 +0000 (UTC) Received: by mail.garage.freebsd.pl (Postfix, from userid 65534) id 210C245CD9; Sat, 23 Oct 2010 10:59:11 +0200 (CEST) Received: from localhost (chello089073192049.chello.pl [89.73.192.49]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.garage.freebsd.pl (Postfix) with ESMTP id 7100345C99; Sat, 23 Oct 2010 10:59:05 +0200 (CEST) Date: Sat, 23 Oct 2010 10:58:32 +0200 From: Pawel Jakub Dawidek To: "Eugene M. Kim" Message-ID: <20101023085832.GD1742@garage.freebsd.pl> References: <4CC215B4.3050607@nttmcl.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="NklN7DEeGtkPCoo3" Content-Disposition: inline In-Reply-To: <4CC215B4.3050607@nttmcl.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 amd64 X-Spam-Checker-Version: SpamAssassin 3.0.4 (2005-06-05) on mail.garage.freebsd.pl X-Spam-Level: X-Spam-Status: No, score=-0.6 required=4.5 tests=BAYES_00,RCVD_IN_SORBS_DUL autolearn=no version=3.0.4 Cc: fs@freebsd.org Subject: Re: ZFS: Parallel I/O to vdevs that appear to be separate physical disks but really are partitions 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: Sat, 23 Oct 2010 08:59:13 -0000 --NklN7DEeGtkPCoo3 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Oct 22, 2010 at 03:52:36PM -0700, Eugene M. Kim wrote: >=20 > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > =20 > Greetings, >=20 > I run a FreeBSD guest in VMware ESXi with a 10GB zpool. Lately the > originally provisioned 10GB proved insufficient, and I would like to > provision another 10GB virtual disk and add it to the zpool as a > top-level vdev. >=20 > The original and new virtual disks are from the same physical pool (a > RAID-5 array), but appears to be separate physical disks to the > FreeBSD guest (da0 and da1). I am afraid that the ZFS would schedule > I/O to the two virtual disks in parallel thinking that the pool > performance will improve, while the performance would actually suffer > due to seeking back and forth between two regions of one physical pool. >=20 > 1. Will ZFS schedule parallel access to different top-level vdevs? Yes, ZFS stripes requests over all top level vdevs. > 2. If so, how can I suggest ZFS that certain vdevs should be treated > not as separate physical disks but as partitions on the same physical > disk? Nope, that's not possible. Instead of adding next 10GB disk maybe it is possible to grow the one you have? ZFS should be able to grow automatically. --=20 Pawel Jakub Dawidek http://www.wheelsystems.com pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --NklN7DEeGtkPCoo3 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.14 (FreeBSD) iEYEARECAAYFAkzCo7cACgkQForvXbEpPzT/YACcDq6bxtlR7oLaRFUZeaQ5nDzM X9gAoK36XBJcZsabNBwbKn8+I06l367T =RNLw -----END PGP SIGNATURE----- --NklN7DEeGtkPCoo3--