From owner-freebsd-stable@FreeBSD.ORG Sat May 14 09:28:49 2005 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 6AEBB16A4CE; Sat, 14 May 2005 09:28:49 +0000 (GMT) Received: from oak.tantieme.ru (oak.tantieme.ru [195.68.129.76]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7B0BE43D7C; Sat, 14 May 2005 09:28:48 +0000 (GMT) (envelope-from vdzh@mail.tantieme.ru) Received: from localhost (localhost [127.0.0.1]) by oak.tantieme.ru (Postfix) with ESMTP id CBA19E0AB5; Sat, 14 May 2005 13:32:21 +0400 (MSD) Received: from oak.tantieme.ru ([127.0.0.1]) by localhost (localhost.tantieme.ru [127.0.0.1]) (amavisd-new, port 10025) with ESMTP id 09715-20; Sat, 14 May 2005 13:32:18 +0400 (MSD) Received: from vdzh (unknown [195.68.129.66]) by oak.tantieme.ru (Postfix) with ESMTP id C6088E082A; Sat, 14 May 2005 13:32:17 +0400 (MSD) From: To: Date: Sat, 14 May 2005 13:22:05 +0400 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <20050514093217.C6088E082A@oak.tantieme.ru> cc: pjd@FreeBSD.org Subject: gmirror X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 14 May 2005 09:28:49 -0000 Hardware: SATA RAID adapter with SiliconImage 3114 chip. 2 SATA HDD. I did gmirror. Run test: 3 parallel tasks "dd if=/dev/mirror/gm0 of=/dev/null bs=1m count=5000" gstat shows summary read speed from mirror about 30-40 mbyte/sec. It is for all balance algorithms: load, round-robin, split While, one "dd if=/dev/ad4 of=/dev/null bs=1m count=5000" shows 50 mbyte/sec 1. Why it occurs and how fix it ? 2. If in the test instead of three instancies of "dd if=/dev/mirror/gm0 of=/dev/null bs=1m count=5000" run only one, then read speed don`t exceeds read speed from one disk (dd if=/dev/ad4 of=/dev/null bs=1m count=5000) a) This is gmirror feature ? b) This is hardware feature (SiliconImage 3114 chip) ?