From owner-freebsd-questions@FreeBSD.ORG Tue Mar 27 01:55:35 2007 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id BB48C16A400 for ; Tue, 27 Mar 2007 01:55:35 +0000 (UTC) (envelope-from freebsd@hub.org) Received: from hub.org (hub.org [200.46.204.220]) by mx1.freebsd.org (Postfix) with ESMTP id 7E00513C4B7 for ; Tue, 27 Mar 2007 01:55:35 +0000 (UTC) (envelope-from freebsd@hub.org) Received: from localhost (unknown [200.46.204.191]) by hub.org (Postfix) with ESMTP id 7459785C8DF for ; Mon, 26 Mar 2007 22:55:29 -0300 (ADT) Received: from hub.org ([200.46.204.220]) by localhost (mx1.hub.org [200.46.204.191]) (amavisd-new, port 10024) with ESMTP id 00479-02 for ; Mon, 26 Mar 2007 22:55:34 -0300 (ADT) Received: from ganymede.hub.org (blk-89-241-126.eastlink.ca [24.89.241.126]) by hub.org (Postfix) with ESMTP id C024485C8DC for ; Mon, 26 Mar 2007 22:55:28 -0300 (ADT) Received: from localhost (localhost [127.0.0.1]) by ganymede.hub.org (Postfix) with ESMTP id C0E2C34980 for ; Mon, 26 Mar 2007 22:55:39 -0300 (ADT) Date: Mon, 26 Mar 2007 22:55:39 -0300 From: "Marc G. Fournier" To: freebsd-questions@freebsd.org Message-ID: X-Mailer: Mulberry/4.0.7 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Subject: mdconfig device no faster then direct disk ... X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Mar 2007 01:55:35 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On a machine that is doing 0 swapping: last pid: 47437; load averages: 0.01, 0.01, 0.00 45 processes: 1 running, 44 sleeping CPU states: 0.0% user, 0.0% nice, 0.4% system, 0.4% interrupt, 99.2% idle Mem: 35M Active, 285M Inact, 271M Wired, 44K Cache, 111M Buf, 402M Free Swap: 2007M Total, 2007M Free I just did: mdconfig -a -t malloc -s 200m -o reserve newfs /dev/md0 Now, my understanding, this builds a file system 'in core', vs on the disk ... with memory being faster then disk, I would have assumed that read/write performance would have been better, but, using iozone, I'm not finding enough of a difference in performance to understand why I'd want to use a memory file system: aster# pwd /usr aster# iozone 180 | grep "the file" It then reads the file. It prints the bytes-per-second Reading the file...1.007812 seconds 54658803 bytes/second for writing the file 187280550 bytes/second for reading the file aster# pwd /usr aster# cd /mnt aster# df . Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/md0 198126 4 182272 0% /mnt aster# iozone 180 | grep "the file" It then reads the file. It prints the bytes-per-second Reading the file...0.984375 seconds 60701485 bytes/second for writing the file 191739611 bytes/second for reading the file Am I missing something here? Or is this expected? - ---- Marc G. Fournier Hub.Org Networking Services (http://www.hub.org) Email . scrappy@hub.org MSN . scrappy@hub.org Yahoo . yscrappy Skype: hub.org ICQ . 7615664 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (FreeBSD) iD8DBQFGCHmb4QvfyHIvDvMRAugAAKDhsRHHeV/0LsQSGLNrLB6cDe2TDgCeMW3i PNL/GimacMHC5W6XWcyIOLo= =a4Tk -----END PGP SIGNATURE-----