From owner-freebsd-questions@FreeBSD.ORG Thu Jun 26 18:00:11 2008 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 EC79C106567A for ; Thu, 26 Jun 2008 18:00:10 +0000 (UTC) (envelope-from david.robillard@gmail.com) Received: from rv-out-0506.google.com (rv-out-0506.google.com [209.85.198.232]) by mx1.freebsd.org (Postfix) with ESMTP id B392E8FC1A for ; Thu, 26 Jun 2008 18:00:10 +0000 (UTC) (envelope-from david.robillard@gmail.com) Received: by rv-out-0506.google.com with SMTP id b25so135176rvf.43 for ; Thu, 26 Jun 2008 11:00:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:mime-version:content-type:content-transfer-encoding :content-disposition; bh=W74GGL1RpIVZrql/iIgoTBN7RlSQSeM1kesuHOVhnPw=; b=b35690C81WvSDhWI6p6ja/5KKzdVoNn49jkJTf5f0ovF/ejBWqyYDZt4/pBF+16Lkd tnQQu/q+MT8VYSBtSsLuPuVTW8wdYD9FLD3B9Kald1cR+hZ6lyBomI8DPIx0+8+Gm1Vm sPXAvJ0RSfZhzz3IeVsVPrUFBZwF62hty+RQg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:mime-version:content-type :content-transfer-encoding:content-disposition; b=JEt1ihedH+shHBCsBlPVDg0Hmv+aadx1oUq2BPXMGh9p9FSSSGCptcdXXPXxV+6XZ1 RUoTLKiXSdhoRs8JFGrP26UwMj3eXDEExU0LQxGQWr48QYMFWCcGPbG2gY1q0O0KZexO uOrcw5J6v5k8fKMXLR238MLo3a6QYzjrFvwog= Received: by 10.141.172.6 with SMTP id z6mr191830rvo.112.1214503210354; Thu, 26 Jun 2008 11:00:10 -0700 (PDT) Received: by 10.141.19.8 with HTTP; Thu, 26 Jun 2008 11:00:10 -0700 (PDT) Message-ID: <226ae0c60806261100n35269756t757cab2f7364bef8@mail.gmail.com> Date: Thu, 26 Jun 2008 14:00:10 -0400 From: "David Robillard" To: prad MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Cc: FreeBSD Questions Subject: Re: to scsi or not to scsi 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, 26 Jun 2008 18:00:11 -0000 > i've heard scsi hard drives are really good. > i've also seen at least one site which claims that ide easily > outperform scsi. I seriously doubt that. Maybe if you take a single old first generation SCSI disk and compare it to a modern IDE drive. But that's not exactly comparing apples to apples. Granted that IDE may beat SCSI in peak performance in a test environment. But IMHO, SCSI is far superior in sustained performance in real life scenarios. > for the server we got (dual P3 1GHz 2M which will use raid), is one > preferable over the other? and what about sata? Choosing between SCSI or IDE or SAS or SATA or FC is mostly a question of Cost, Performance, Reliability and Expected Workload. If you plan to have two users on that dual P3 machine, then go for any cheap drive in RAID1, be it IDE or SATA. That's going to work alright. But if you're going to install a database on this machine with 100+ concurent users. Then I'd go for SCSI or SAS (and a new hardware for that matter :) Generally speaking, SCSI, SAS and FC disks are Enterprise class disks while IDE and SATA are Workstation/Home class disks. SCSI/SAS/FC disks are not cheap, but more robust (i.e. MTBF is better then for IDE/SATA disks) and generally faster (I've never seen a 15,000 rpm IDE disk for instance). You use SCSI/SAS/FC disks for high workload machines where you need speed and reliability (such as Oracle databases, Java Application servers, Microsoft Exchange servers or ERP servers for instance). You use IDE/SATA on easy workloads or when you prefer disk space over speed and reliability. FC disks are usually found in Enterprise storage arrays sold by EMC, NetApp, StorageTek, IBM, HP and friends. You might be interested in reading chapter 7 from "Linux Administration Handbook, 2nd ed" from Nemeth, Snyder, Hein & al at Prentice Hall publishing. Or http://www.scsi-planet.com/vs/ Cheers, David -- David Robillard UNIX systems administrator & Oracle DBA CISSP, RHCE & Sun Certified Security Administrator Montreal: +1 514 966 0122 If you receive something that says "Send this to everyone you know", then please pretend you don't know me.