From owner-freebsd-performance@FreeBSD.ORG Tue Nov 6 17:54:10 2007 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E72D816A417 for ; Tue, 6 Nov 2007 17:54:10 +0000 (UTC) (envelope-from mgowda82@gmail.com) Received: from wa-out-1112.google.com (wa-out-1112.google.com [209.85.146.177]) by mx1.freebsd.org (Postfix) with ESMTP id B7E6013C4B9 for ; Tue, 6 Nov 2007 17:54:10 +0000 (UTC) (envelope-from mgowda82@gmail.com) Received: by wa-out-1112.google.com with SMTP id k17so2612579waf for ; Tue, 06 Nov 2007 09:54:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; bh=/7QaR4xRYUL58qdBUFd4R2YJcU/nG5ekz095UvboOqM=; b=DAqjH5DS3MpuiaIVzK980eGlbUIVhfrGd0DK4hS0PFNmqaq8CxFPnaqFW5HnQjpXgaaEwHkpql6AlW9LezdBHiEDWA0SHx7fFJJHMF2qTqaVx/R+2wYa5XotBAdOPgkGNAwGNS8lrz2xqJ1Z4sAAttYhyWSpc5D5YsBmXT+mfQk= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; b=oTTFn67OYjq8/cBZ5/iNaqaEb1iUuJxZ/+a28T2UCWwXWs/QGnXUcpDtaArD8HO6OHdyzgGOl4kxyMUEOdnpriJdaGHJCYWe4dquU+aF6v6L9/1y3+LNXRAtuTzsCUPwhnF75RXr57DZrwLJN76hh28aHn/z4VM4vfS3Z/4dfZY= Received: by 10.114.27.20 with SMTP id a20mr504695waa.1194371649388; Tue, 06 Nov 2007 09:54:09 -0800 (PST) Received: by 10.114.123.4 with HTTP; Tue, 6 Nov 2007 09:54:09 -0800 (PST) Message-ID: Date: Tue, 6 Nov 2007 09:54:09 -0800 From: "Manjunath R Gowda" To: "Nico -telmich- Schottelius" In-Reply-To: <20071106122820.GA28254@schottelius.org> MIME-Version: 1.0 References: <20071106122820.GA28254@schottelius.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-performance@freebsd.org Subject: Re: Performance of disk i/o with 3ware X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 06 Nov 2007 17:54:11 -0000 On 11/6/07, Nico -telmich- Schottelius < nico-freebsd-performance@schottelius.org> wrote: > > Hello! > > I've the problem that sometimes there are many disk waiting processes > (sysctl -n vm.vmtotal), but systat -vmstat shows da0 and da1 busy with > 0-10%. I woudn't worry about how many are sleeping. But, How long they sleep would be interesting data. I guess that the disk i/o is at about 100%, but wondering why I see > those strange values. Why do you think it should be 100%? Are you running any disk I/O intense application? System Information: > > - Disks are attached to 07:01.0 RAID bus controller: 3ware Inc 9550SX > SATA-RAID > > u0216# uname -a > FreeBSD u0216.nshq.netstream.com 6.2-RELEASE FreeBSD 6.2-RELEASE #0: Wed > Oct 31 14:53:00 CET 2007 root@u0216.nshq.netstream.com > :/usr/obj/usr/src/sys/SMPPAEQUOTA i386 > > => kernel contains 3ware patches from CVS, marked for inclusion in 6.3, > because we've seen many times a freeze on that system before > > - Disks are 10k rpm sata disks. > - Board is a Supermicro X7DB8, processor is a quad core Xeon, > E5345@2.33GHz. > > Anyone an idea, > a) why systat -vmstat shows so small busy values? > b) how to debug it further? You can try experimenting with diffrent I/O loads to make sure that there is a problem before start debugging it. -Manjunath