From owner-freebsd-isp@FreeBSD.ORG Tue Oct 19 21:23:37 2004 Return-Path: Delivered-To: freebsd-isp@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 66CC616A4D6 for ; Tue, 19 Oct 2004 21:23:37 +0000 (GMT) Received: from wjv.com (fl-65-40-24-38.sta.sprint-hsd.net [65.40.24.38]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9101A43D2F for ; Tue, 19 Oct 2004 21:23:36 +0000 (GMT) (envelope-from bv@bilver.wjv.com) Received: from bilver.wjv.com (localhost.wjv.com [127.0.0.1]) by wjv.com (8.12.11/8.13.1) with ESMTP id i9JLIQ7o055972; Tue, 19 Oct 2004 17:18:26 -0400 (EDT) (envelope-from bv@bilver.wjv.com) Received: (from bv@localhost) by bilver.wjv.com (8.12.11/8.12.11/Submit) id i9JLIQFl055971; Tue, 19 Oct 2004 17:18:26 -0400 (EDT) (envelope-from bv) Date: Tue, 19 Oct 2004 17:18:26 -0400 From: Bill Vermillion To: Kristofer Pettijohn Message-ID: <20041019211826.GB55676@wjv.com> References: <20041019192252.GB78974@cybernetik.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041019192252.GB78974@cybernetik.net> Organization: W.J.Vermillion / Orlando - Winter Park ReplyTo: bv@wjv.com User-Agent: Mutt/1.5.6i X-Spam-Status: No, hits=0.0 required=5.0 tests=none autolearn=no version=2.64 X-Spam-Checker-Version: SpamAssassin 2.64 (2004-01-11) on bilver.wjv.com cc: freebsd-isp@freebsd.org Subject: Re: Disk I/O Performance with CCD X-BeenThere: freebsd-isp@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: bv@wjv.com List-Id: Internet Services Providers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 Oct 2004 21:23:37 -0000 Ashes to ashes, and DOS to DOS Kristofer Pettijohn was heard to say on or about Tue, Oct 19, 2004 at 14:22 : > Im looking for some suggestions on I/O performance. > I'm using FreeBSD 4.10-RELEASE on a Usenet transit server running > Diablo for the transit software. > I have 4 Seagate ST373435LC SCSI drives, 70GB each, and I am using > CCD to bind them together with RAID-0 stripes. > I can pull in anywhere from 30-40 MB sec and push out ~ 8-15 MB/sec.. > averaging about 50 MB/sec throughput.. feeds coming in are coming > in just fine, but sending stuff back out is lagging behind.. its > falling about a half hour behind every hour. > > I've used tunefs to set the average file size to 20 MB and enabled > soft-updates, as these are generally larger binary files that just > get appended to, and then seeked later on to send the article out, > I've played with setting the stripe size from anywhere between 8MB > and 64MB, and did not see much change on performance between those. > > Maybe I'm just missing something small, but on these SCSI drives > which have 160 MB/s transfer rates, I'm expecting a bit more than > I'm getting with CCD. > Can someone give me any pointers to look at or suggestions of things > to try? Why not run one of the benchmarks to see what your disk I/O looks like through the filesystem. I've been using the old Iozone 2.1 for about 10 years - it's simple and only tests throught through the filesystem. I save a copy of the output when I first install a system and then if things appear slow later I'll run it again to see if it did slow down or that I remembered the speeds differently. It's under /usr/ports/benchmarks/iozone21. Bill -- Bill Vermillion - bv @ wjv . com