From owner-freebsd-questions@FreeBSD.ORG Wed May 13 14:05:11 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0B28510656AE for ; Wed, 13 May 2009 14:05:11 +0000 (UTC) (envelope-from tijl@ulyssis.org) Received: from mailrelay012.isp.belgacom.be (mailrelay012.isp.belgacom.be [195.238.6.179]) by mx1.freebsd.org (Postfix) with ESMTP id 9C2008FC12 for ; Wed, 13 May 2009 14:05:10 +0000 (UTC) (envelope-from tijl@ulyssis.org) X-Belgacom-Dynamic: yes X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AkkFADBwCkpR927y/2dsb2JhbACBUM1+hAIF Received: from 242.110-247-81.adsl-dyn.isp.belgacom.be (HELO kalimero.kotnet.org) ([81.247.110.242]) by relay.skynet.be with ESMTP; 13 May 2009 16:05:08 +0200 Received: from kalimero.kotnet.org (kalimero.kotnet.org [127.0.0.1]) by kalimero.kotnet.org (8.14.3/8.14.3) with ESMTP id n4DE546B003492; Wed, 13 May 2009 16:05:05 +0200 (CEST) (envelope-from tijl@ulyssis.org) From: Tijl Coosemans To: freebsd-questions@freebsd.org, Andy Dills Date: Wed, 13 May 2009 16:05:03 +0200 User-Agent: KMail/1.9.10 References: <20090512135226.N64283@shell.xecu.net> In-Reply-To: <20090512135226.N64283@shell.xecu.net> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200905131605.04534.tijl@ulyssis.org> Cc: Subject: Re: Extreme filesystem performance decrese going from FreeBSD4 to FreeBSD7 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: Wed, 13 May 2009 14:05:11 -0000 On Tuesday 12 May 2009 20:16:21 Andy Dills wrote: > A customer of a customer needed to expand the size of the filesystem > on a webserver they run, and since it was still running 4.11, they > decided to go ahead and upgrade to 7.1. > > Unfortunately, they have seen the performance decrease significantly. > Now, under 7.1, numerous perl processes will queue up (from their web > applications), the load average will be in the 40s to 90s, and > according to top they perl scripts are commonly in the "ufs" state, > which I assume means stuck waiting for read or write responses. > > I have also experienced pretty abysmal read performance from the > array, using dd...we're talking sub 1MBps. So, my assumption is that > something is wrong on the filesystem layer. > > When I look at the CPU utilization in top, I see that 80-90% is > constantly used by "system". > > However, when I look at iostat, I see very low numbers for the raid, > in fact across the board. > > It's a Dell server with a Perc4/Di RAID controller, which uses the > amr driver. They upgraded to larger, 15k rpm ultra 320 disks (from > smaller 15k rpm ultra 320 disks). They made a backup of their web > root, which is a seperate partition, using dump to a temporary drive, > then swapped in the new disks, installed FreeBSD 7.1, and restored > their webroot to a partition on the new array. > > Does anybody have any insight into what could be going on here? I believe there was a performance regression in 7.1 for SCSI disks. I don't know if the amr driver was affected but the issues should be resolved in FreeBSD 7.2 so you might want to give that a try.