From owner-freebsd-scsi@FreeBSD.ORG Thu Aug 30 12:58:08 2007 Return-Path: Delivered-To: freebsd-scsi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2FBA516A469; Thu, 30 Aug 2007 12:58:08 +0000 (UTC) (envelope-from scottl@samsco.org) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.freebsd.org (Postfix) with ESMTP id B5D3E13C4A5; Thu, 30 Aug 2007 12:58:07 +0000 (UTC) (envelope-from scottl@samsco.org) Received: from phobos.samsco.home (phobos.samsco.home [192.168.254.11]) (authenticated bits=0) by pooker.samsco.org (8.13.8/8.13.8) with ESMTP id l7UCvlSl038016; Thu, 30 Aug 2007 06:57:48 -0600 (MDT) (envelope-from scottl@samsco.org) Message-ID: <46D6BEC0.1050104@samsco.org> Date: Thu, 30 Aug 2007 06:57:36 -0600 From: Scott Long User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.1.6) Gecko/20070802 SeaMonkey/1.1.4 MIME-Version: 1.0 To: "Lutieri G." References: <71d0ebb0708291245g79d2141fx73cc8a6e76875944@mail.gmail.com> <46D5E17F.3070403@samsco.org> <71d0ebb0708291416v17351c65u7ccc1b7bbe0271d2@mail.gmail.com> <46D5E5B1.207@samsco.org> <71d0ebb0708291506i49649a60l8006deafb20891ac@mail.gmail.com> <46D63710.1020103@freebsd.org> <71d0ebb0708300502x632fe83bo617f84ca2008dc7d@mail.gmail.com> In-Reply-To: <71d0ebb0708300502x632fe83bo617f84ca2008dc7d@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (pooker.samsco.org [168.103.85.57]); Thu, 30 Aug 2007 06:57:48 -0600 (MDT) X-Spam-Status: No, score=-1.4 required=5.5 tests=ALL_TRUSTED autolearn=failed version=3.1.8 X-Spam-Checker-Version: SpamAssassin 3.1.8 (2007-02-13) on pooker.samsco.org Cc: FREEBSD - SCSI - LIST Subject: Re: performance with LSI SAS 1064 X-BeenThere: freebsd-scsi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SCSI subsystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 30 Aug 2007 12:58:08 -0000 Lutieri G. wrote: > 2007/8/30, Eric Anderson : >> I'm confused - you said in your first post you were getting 3MB/s, where >> above you show something like 55MB/s. > Sorry! using blogbench i got 3MB/s and 100% busy. Once is 100% busy i > thinked that 3MB/s is the maximum speed. But i was wrong... %busy is a completely useless number for a anything but untagged, uncached disk subsystems. It's only an indirect measure of latency, and there are better tools for measuring latency (gstat). >> You didn't say what kind of disks, or how many, the configuration, etc - >> so it's hard to answer much. The 55MB/s seems pretty decent for many >> hard drives in a sequential use state (which is what dd tests really). >> > SAS disks. Seagate, i don't know what is the right model of disks. > > Ok. If 55Mb/s is a decent speed i'm happy. I'm getting problems with > squid cache and maybe should be a problem related with disks. But... > i'm investigating and discharging problems. > > >> Your errors before were probably caused because your queue depth is set >> to 255 (or 256?) and the adapter can't do that many. You should use >> camcontrol to reduce it, to maybe 32. See the camcontrol man page for >> the right usage. It's something that needs setting on every boot, so a >> startup file is a good place for it maybe. >> > Is there any way of get the right number to reduce?! > If you're seeing erratic performance in production _AND_ you're seeing lots of accompanying messages on the console about tag depth jumping around, you can use camcontrol to force the depth to a lower number of you're choosing. This kind of problem is pretty rare, though. Scott