From owner-freebsd-performance@FreeBSD.ORG Thu Dec 9 17:06:56 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 D985616A4CE for ; Thu, 9 Dec 2004 17:06:56 +0000 (GMT) Received: from mail.geeks.org (jacobs.Geeks.ORG [204.153.247.1]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2BA7143D39 for ; Thu, 9 Dec 2004 17:06:56 +0000 (GMT) (envelope-from drechsau@Geeks.ORG) Received: by mail.geeks.org (Postfix, from userid 400) id 781DB20B55; Thu, 9 Dec 2004 11:06:55 -0600 (CST) Date: Thu, 9 Dec 2004 11:06:55 -0600 From: Mike Horwath To: Bill Anderson Message-ID: <20041209170655.GH45512@octanews.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-PGP-Fingerprint: D8 24 CC E6 47 5F E4 60 BF B7 6E FA BF C7 6E C5 X-GPG-Fingerprint: 6A89 E78A B8B1 69D9 8CDB E966 4A5A C3F9 A1B0 C381 User-Agent: Mutt/1.5.6i cc: freebsd-performance@freebsd.org Subject: Re: 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: Thu, 09 Dec 2004 17:06:57 -0000 On Wed, Dec 08, 2004 at 11:51:21AM -0500, Bill Anderson wrote: > 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) I know I left quite a bit of cruft above, but I don't see these kinds of performance numbers you are seeing. First, SCSI does a lot with overlapping I/O and tagged queuing, only the newest IDE (SATA) systems are starting to support such things. Second, SCSI disks run at a faster RPM most of the time (only the WD Raptor hits the 10K mark), lowering seek time significantly. Third, my numbers: 31MB/sec using dd if=/dev/aacd0s1b of=/dev/null bs=32k count=20000 34MB/sec using dd if=/dev/aacd0s1b of=/dev/null bs=64k count=20000 33MB/sec using dd if=/dev/aacd0s1b of=/dev/null bs=128k count=20000 Now, go and do some testing with random reads and writes and you will see a big difference between your standard IDE disk and this RAID system. The system I was tesing with was loaded down with MySQL operating with 320 tables open, 110 connections, and 128 queries per second, including one table with 9.7M records and 3.2GB in size. The system only has 2GB of RAM. I use the aac driver for a few of my news feeder boxes, I do primary storage of my history on a mounted md but I also do all of my other work via an aac driven RAID5 partition for the things I worry about. The spool is on an external system and doesn't count :) (the external system reaches upwards of 70MB/sec using the test above via 1Gbps FC, and is storaged by WD Raptor SATA 74GB disks). Each of these boxes handles 1.4TB of inbound news per day, and each have been doing 2TB outbound...the RAID systems have been fine... I also use the amrd driver on my Dell frontend systems for news using RAID5 and 3x73GB 10K disks, with upwards of 320-450 connections per server, no issues from the disk subsystems... Again, random reads and writes are what you might want to worry about, sequential R/W doesn't happen in a real work environment, at least not for me. -- Mike Horwath, reachable via drechsau@Geeks.ORG