From owner-freebsd-questions@FreeBSD.ORG Thu Nov 30 18:39:12 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 8315616A492 for ; Thu, 30 Nov 2006 18:39:12 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from smtpout.mac.com (smtpout.mac.com [17.250.248.184]) by mx1.FreeBSD.org (Postfix) with ESMTP id 81CB743C9D for ; Thu, 30 Nov 2006 18:39:01 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from mac.com (smtpin05-en2 [10.13.10.150]) by smtpout.mac.com (Xserve/8.12.11/smtpout14/MantshX 4.0) with ESMTP id kAUIdA9b023334; Thu, 30 Nov 2006 10:39:10 -0800 (PST) Received: from [17.214.13.96] (a17-214-13-96.apple.com [17.214.13.96]) (authenticated bits=0) by mac.com (Xserve/smtpin05/MantshX 4.0) with ESMTP id kAUId8gu018268; Thu, 30 Nov 2006 10:39:08 -0800 (PST) In-Reply-To: <8A1C4E8F-5409-4A75-AB61-2475F1688330@vfs.com> References: <8A1C4E8F-5409-4A75-AB61-2475F1688330@vfs.com> Mime-Version: 1.0 (Apple Message framework v752.2) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: Content-Transfer-Encoding: 7bit From: Chuck Swiger Date: Thu, 30 Nov 2006 10:39:07 -0800 To: Derrick MacPherson X-Mailer: Apple Mail (2.752.2) X-Brightmail-Tracker: AAAAAA== X-Brightmail-scanned: yes Cc: freebsd-questions@freebsd.org Subject: Re: degraded RAID performance after OS upgrade, and drives added. X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 30 Nov 2006 18:39:12 -0000 On Nov 29, 2006, at 6:18 PM, Derrick MacPherson wrote: > We updated to 6.1 this weekend and added 3 300gb drives to the > external raid cabinet, they were to go on a seprate controller but > the server happens to have a few other boxes on top making it > impossible at that time, so we put the 3x300 (RAID5) , upgraded > the OS and performance is very poor. When I run systat I see > upward of 300 tps on the problematic array (da2) and under systat - > vmstat : It's normal for RAID-5 to perform worse than a single drive-- and sometimes it performs much worse, as in nearly an order of magnitude slower, for the case of very small writes. If you value performance, choose another RAID level like RAID-0, RAID-1, or RAID-10. -- -Chuck