From owner-freebsd-performance@FreeBSD.ORG Wed Dec 8 16:51:23 2004 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1B6AA16A4CE for ; Wed, 8 Dec 2004 16:51:23 +0000 (GMT) Received: from tardis.uts.ohio-state.edu (tardis.uts.ohio-state.edu [128.146.116.116]) by mx1.FreeBSD.org (Postfix) with ESMTP id C6B1B43D5D for ; Wed, 8 Dec 2004 16:51:22 +0000 (GMT) (envelope-from anderson@wks.uts.ohio-state.edu) Received: from lennier.uts.ohio-state.edu (lennier.uts.ohio-state.edu [128.146.116.7])iB8GpMhi008235 for ; Wed, 8 Dec 2004 11:51:22 -0500 (EST) Date: Wed, 8 Dec 2004 11:51:21 -0500 (EST) From: Bill Anderson X-X-Sender: To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Subject: 2120S poor performance X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 08 Dec 2004 16:51:23 -0000 I've got a 3x72g RAID5 array with U320 disks on an Adaptec 2120S controller under Freebsd 4.10. I'm getting about 25MB/s for sequential reads/writes (e.g. dd if=/dev/aacd0s1b of=/dev/null bs=32k). I've turned on write caching for the container (container set cache /write_cache_enable) and turned off the read caching, per previous posts to this list. I'm going to try setting hw.aac.iosize_max to 96k tonight to see if that helps. I'm currently using an IDE disk that gets about 45MB/s, so I can hardly consider it an "upgrade" to switch to a 25MB/s U320 SCSI system. :/ I've also read that the 2120S is slow because of its design. I'm trying to figure out whether the performance can be increased significantly (I saw a posting of a linux user getting 37.5MB/s, which although still slow might be acceptable), or if I'm better off getting a new card. I'm thinking the latter is the case based on previous postings, but since it will probably be quite expensive to replace it, I wanted to get some more data. What performance should I be expecting from a decent U320 RAID5 controller? Has anyone gotten a 2120S to perform above 30Mb/s in FreeBSD? What's the cheapest controller that still gives reasonable performance? (If you could give a couple different ones, with their associated performance (under FreeBSD), or tell me where to find such information, that would be great) Thanks, Bill