From owner-freebsd-geom@FreeBSD.ORG Tue Sep 25 10:41:45 2007 Return-Path: Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DBF0B16A419; Tue, 25 Sep 2007 10:41:45 +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 64BBA13C447; Tue, 25 Sep 2007 10:41:45 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: by mail.garage.freebsd.pl (Postfix, from userid 65534) id 0D9A745E90; Tue, 25 Sep 2007 12:41:43 +0200 (CEST) Received: from localhost (pjd.wheel.pl [10.0.1.1]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.garage.freebsd.pl (Postfix) with ESMTP id F33F345B26; Tue, 25 Sep 2007 12:41:38 +0200 (CEST) Date: Tue, 25 Sep 2007 12:40:10 +0200 From: Pawel Jakub Dawidek To: Ivan Voras Message-ID: <20070925104010.GA1572@garage.freebsd.pl> References: <20070921143318.GC5690@garage.freebsd.pl> <20070921170506.GB9445@garage.freebsd.pl> <1310567292.20070921235802@gmail.com> <20070922011847.GH9445@garage.freebsd.pl> <1231480340.20070922112446@gmail.com> <20070922111958.GA1614@garage.freebsd.pl> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="qMm9M+Fa2AknHoGS" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i X-PGP-Key-URL: http://people.freebsd.org/~pjd/pjd.asc X-OS: FreeBSD 7.0-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=3.0 tests=ALL_TRUSTED,BAYES_00 autolearn=ham version=3.0.4 Cc: freebsd-geom@freebsd.org Subject: Re: raidtest for zfs 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: Tue, 25 Sep 2007 10:41:45 -0000 --qMm9M+Fa2AknHoGS Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Sep 23, 2007 at 11:35:15PM +0200, Ivan Voras wrote: > Pawel Jakub Dawidek wrote: >=20 > > ZFS ZVOL doesn't present raw blocks to use, like graid3/graid5, so it's > > quite possible that because of how the data was written and how ZFS > > prefetches the data it's faster than one disk. >=20 > So does ZVOL actually offer "cooked" data to its users (caching, lazy > allocation?), similar to what would happen if the entire ZVOL was one > big file in a "normal" ZFS file system? Yes. > Slightly off-topic: for most file systems, it used to be recommended > that "lots of smallish files" be distributed in lots of directories in a > radix-like fashion instead of keeping all files in one huge directory. > Do you know if ZFS does something to help this situation, or are the old > rules of thumb still applicable? ZFS uses extendable hash data structure for directory entires, but you would need to test it on your own to see if its fast enough for your needs. --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --qMm9M+Fa2AknHoGS Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFG+OWKForvXbEpPzQRAiAVAKCgwqtqJa6Q5Lgprmf+uppPgjK1uQCfWX1e WMHjWMkhux6w+PZL7Eo4Gs4= =P3Ge -----END PGP SIGNATURE----- --qMm9M+Fa2AknHoGS--