From fork-admin@xent.com Tue Sep 17 11:29:50 2002 Return-Path: Delivered-To: yyyy@localhost.example.com Received: from localhost (jalapeno [127.0.0.1]) by jmason.org (Postfix) with ESMTP id DB4C516F03 for ; Tue, 17 Sep 2002 11:29:49 +0100 (IST) Received: from jalapeno [127.0.0.1] by localhost with IMAP (fetchmail-5.9.0) for jm@localhost (single-drop); Tue, 17 Sep 2002 11:29:49 +0100 (IST) Received: from xent.com ([64.161.22.236]) by dogma.slashnull.org (8.11.6/8.11.6) with ESMTP id g8GJhcC07013 for ; Mon, 16 Sep 2002 20:43:39 +0100 Received: from lair.xent.com (localhost [127.0.0.1]) by xent.com (Postfix) with ESMTP id 89BE82940D0; Mon, 16 Sep 2002 12:40:05 -0700 (PDT) Delivered-To: fork@example.com Received: from venus.phpwebhosting.com (venus.phpwebhosting.com [64.29.16.27]) by xent.com (Postfix) with SMTP id B6F8B2940CD for ; Mon, 16 Sep 2002 12:39:05 -0700 (PDT) Received: (qmail 8446 invoked by uid 508); 16 Sep 2002 19:43:47 -0000 Received: from unknown (HELO hydrogen.leitl.org) (62.155.144.96) by venus.phpwebhosting.com with SMTP; 16 Sep 2002 19:43:47 -0000 Received: from localhost (eugen@localhost) by hydrogen.leitl.org (8.11.6/8.11.6) with ESMTP id g8GJBlB15944; Mon, 16 Sep 2002 21:11:47 +0200 X-Authentication-Warning: hydrogen.leitl.org: eugen owned process doing -bs From: Eugen Leitl To: Cc: Gary Lawrence Murphy , Udhay Shankar N , Adam Rifkin , Subject: Re: storage bits In-Reply-To: <3D862A52.1080502@hpti.com> Message-Id: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: fork-admin@xent.com Errors-To: fork-admin@xent.com X-Beenthere: fork@example.com X-Mailman-Version: 2.0.11 Precedence: bulk List-Help: List-Post: List-Subscribe: , List-Id: Friends of Rohit Khare List-Unsubscribe: , List-Archive: Date: Mon, 16 Sep 2002 21:11:47 +0200 (CEST) X-Spam-Status: No, hits=-11.1 required=7.0 tests=EMAIL_ATTRIBUTION,IN_REP_TO,KNOWN_MAILING_LIST, QUOTED_EMAIL_TEXT,SPAM_PHRASE_00_01,USER_AGENT_PINE, X_AUTH_WARNING version=2.50-cvs X-Spam-Level: On Mon, 16 Sep 2002, Stephen D. Williams wrote: > It's efficient-end, not low end. At 1Million hour MTBF, 133MB/sec, > and pretty good buffering and speed, the only thing going for SCSI is > 15,000 RPM vs. 7200 and in a very small number of cases, slightly > better scatter-gather. (Actually, I think there might be a 15,000 RPM > IDE now.) It's not just krpm, the desktop HDs have a higher failure rate. But I agree, EIDE has high density, and EIDE hardware RAID can offer SCSI a sound beating for reliability, performance, and storage density/rack units for the money, if designed for it, and if people would actually start buying it. > The other issues are pretty much non-issues: using multiple drives and > controller contention (just use many IDE channels with extra PCI > cards, up to 10 in some systems), and long cable runs (just split There are not all that many hard drives inside an 1U enclosure. Airflow blockage (you have to fit in 2-3x the number of SCSI disks with EIDE) will soon be a thing of the past due to SATA. > storage between nodes). Dual-port SCSI is also a non-issue since it > is very expensive, doesn't work that well in practice because there > are numerous secondary failure modes for shared disk systems, and > because you still end up with a single point of failure. Since rack-space costs dominate, and our systems need more or less decent I/O we're going with 1U Dells with SCSI. The hard drive prices don't really make a visible difference, given the cost of the iron, and the rackspace/month. Plus, 1U Dells don't have any space left for lots of EIDE drives.