From owner-freebsd-performance@FreeBSD.ORG Tue Apr 15 19:48:48 2003 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 62CEB37B401 for ; Tue, 15 Apr 2003 19:48:48 -0700 (PDT) Received: from mailserv.ait.ac.th (mailserv.ait.ac.th [203.159.5.10]) by mx1.FreeBSD.org (Postfix) with ESMTP id 993E643F85 for ; Tue, 15 Apr 2003 19:48:47 -0700 (PDT) (envelope-from alain@ait.ac.th) Received: from localhost (mailserv.ait.ac.th [127.0.0.1]) by mailserv.ait.ac.th (Postfix) with ESMTP id 64D66113FBB; Wed, 16 Apr 2003 09:48:46 +0700 (ICT) Received: from alain.ait.ac.th (alain.itserv.ait.ac.th [203.159.28.4]) by mailserv.ait.ac.th (Postfix) with ESMTP id 846F0113F36; Wed, 16 Apr 2003 09:48:45 +0700 (ICT) Received: (from alain@localhost) by alain.ait.ac.th (8.12.4/8.12.4) id h3G2miK7028348; Wed, 16 Apr 2003 09:48:44 +0700 Date: Wed, 16 Apr 2003 09:48:44 +0700 From: Alain Fauconnet To: Jason Stone Message-ID: <20030416024844.GC7867@ait.ac.th> References: <20030416021004.GA7867@ait.ac.th> <20030415192851.G4074-100000@walter> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030415192851.G4074-100000@walter> User-Agent: Mutt/1.4i X-Virus-Scanned: by AMaViS perl-11 cc: freebsd-performance@freebsd.org Subject: Re: tweaking FreeBSD for Squid using X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 16 Apr 2003 02:48:48 -0000 On Tue, Apr 15, 2003 at 07:31:24PM -0700, Jason Stone wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > > > You didn't mention whether is it SCSI or IDE. > > Based on the fact that it's 15k rpms, I'm guessing scsi - do ide disks > faster than 7.2k rpms exist? I don't know. Seems that IDE disks evolve too fast for me nowadays. That's also why I was writing that I'm not even sure that the old stance "don't use IDE for servers" is still valid. OOTH, I've had a lot of trouble with busy IDE-based (ASUS P4* m/b) FreeBSD servers lately (hard hangs, see bug kern/44867). > > > > Don't do RAID. Bring up a filesystem on each disk (with soft updates > > of course), mount them "-o noatime" and configure Squid to use > > multiple cache dirs. > > Why is this preferrable to striping with raid-0? Well, because Squid does load balancing over multiple cache dirs quite well by itself, and (presumably) in a smarter way than just spreading raw disk blocks, so adding another layer of software for RAID-0 doesn't bring anything, and wastes CPU cycles. I'm not even sure that hardware RAID-0 is a good idea. According to my own experience (admittedly on a Linux box), removing software striping and using multiple cache dirs on physical volumes gave me a significant performance boost and lowered the load average of the server by about 30%. Since then, I've always stayed away from RAID on Squid boxes, whatever the O/S. Er. This is getting off topic maybe. I'll follow up privately if needed. _Alain_