From owner-freebsd-stable@FreeBSD.ORG Mon Nov 26 15:26:30 2007 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id ABCCA16A41B for ; Mon, 26 Nov 2007 15:26:30 +0000 (UTC) (envelope-from cmarlatt@rxsec.com) Received: from core.rxsec.com (core.rxsec.com [64.132.46.102]) by mx1.freebsd.org (Postfix) with SMTP id 56B2213C4F3 for ; Mon, 26 Nov 2007 15:26:30 +0000 (UTC) (envelope-from cmarlatt@rxsec.com) Received: (qmail 57972 invoked by uid 2009); 26 Nov 2007 14:51:01 -0000 Received: from 10.1.0.230 by core.rxsec.com (envelope-from , uid 2008) with qmail-scanner-1.25-st-qms (clamdscan: 0.86.2/1102. spamassassin: 3.0.4. perlscan: 1.25-st-qms. Clear:RC:0(10.1.0.230):SA:0(-4.4/5.0):. Processed in 4.861876 secs); 26 Nov 2007 14:51:01 -0000 X-Spam-Status: No, hits=-4.4 required=5.0 X-Antivirus-RXSEC-Mail-From: cmarlatt@rxsec.com via core.rxsec.com X-Antivirus-RXSEC: 1.25-st-qms (Clear:RC:0(10.1.0.230):SA:0(-4.4/5.0):. Processed in 4.861876 secs Process 57957) Received: from unknown (HELO ?10.13.100.31?) (cmarlatt@rxsec.com@10.1.0.230) by core.rxsec.com with SMTP; 26 Nov 2007 14:50:56 -0000 Message-ID: <474ADF4F.7090303@rxsec.com> Date: Mon, 26 Nov 2007 09:59:27 -0500 From: Chris Marlatt Organization: Receive Security User-Agent: Thunderbird 2.0.0.9 (Windows/20071031) MIME-Version: 1.0 To: =?UTF-8?B?6Z+T5a625qiZIEJpbGwgSGFja2Vy?= References: <47496BE1.8080206@modula.no> <474988C0.4070909@conducive.net> In-Reply-To: <474988C0.4070909@conducive.net> X-Enigmail-Version: 0.95.5 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: freebsd-stable@freebsd.org Subject: Re: SAS5IR performance issue with Dell 860 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Nov 2007 15:26:30 -0000 韓家標 Bill Hacker wrote: > > You haven't indicated what drives are on that controller, or how (RAID?) > arranged.,, what sort of on-drive or on-controller cahce and policy. > > Nor how you measured the '..performs better', which a single > can often do compared to several of the possible RAID configurations. > > Otherwise, those are not actually 'bad' numbers for sustained I/O - > especially if anything-at-all is going on at the same time that needs to > intervene and move the r/w heads 'elsewhere' - however briefly. > > More info? > > Bill > The issue has already been confirmed and a "fix"/hack committed so there's little point busting his balls for lack of information in his email. It seems like he was only requesting any updated information on the issue, not a full diagnosis. The Dell PE-860 only comes with 2 drives, so its going to be independent drives, raid 1, or raid 0. Frankly if independent drives or raid 0 are performing that poorly as well it would seem the issue is even worse than previously indicated. As for the cache policy, seeing as that's the fix, your question seems a little odd. Best regards, Chris