Return-Path: X-Original-To: apmail-hadoop-general-archive@minotaur.apache.org Delivered-To: apmail-hadoop-general-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 018B677BE for ; Sat, 13 Aug 2011 19:24:09 +0000 (UTC) Received: (qmail 7141 invoked by uid 500); 13 Aug 2011 19:24:06 -0000 Delivered-To: apmail-hadoop-general-archive@hadoop.apache.org Received: (qmail 7022 invoked by uid 500); 13 Aug 2011 19:24:05 -0000 Mailing-List: contact general-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: general@hadoop.apache.org Delivered-To: mailing list general@hadoop.apache.org Received: (qmail 7011 invoked by uid 99); 13 Aug 2011 19:24:05 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Sat, 13 Aug 2011 19:24:05 +0000 X-ASF-Spam-Status: No, hits=-1.6 required=5.0 tests=RCVD_IN_DNSWL_MED,SPF_NEUTRAL X-Spam-Check-By: apache.org Received-SPF: neutral (athena.apache.org: local policy) Received: from [192.6.10.60] (HELO tobor.hpl.hp.com) (192.6.10.60) by apache.org (qpsmtpd/0.29) with ESMTP; Sat, 13 Aug 2011 19:23:57 +0000 Received: from localhost (localhost [127.0.0.1]) by tobor.hpl.hp.com (Postfix) with ESMTP id 8776BB7FE9 for ; Sat, 13 Aug 2011 20:23:36 +0100 (BST) X-Virus-Scanned: amavisd-new at hplb.hpl.hp.com Received: from tobor.hpl.hp.com ([127.0.0.1]) by localhost (tobor.hpl.hp.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id JQSPj1KE9utP for ; Sat, 13 Aug 2011 20:23:35 +0100 (BST) Received: from 0-imap-br1.hpl.hp.com (0-imap-br1.hpl.hp.com [16.25.144.60]) by tobor.hpl.hp.com (Postfix) with ESMTP id 948CEB7FE7 for ; Sat, 13 Aug 2011 20:23:35 +0100 (BST) MailScanner-NULL-Check: 1313868200.39889@7uNaeIZA3+/fAlRdzswuwg Received: from [16.24.234.172] ([16.24.234.172]) by 0-imap-br1.hpl.hp.com (8.14.1/8.13.4) with ESMTP id p7DJNISU026273 for ; Sat, 13 Aug 2011 20:23:18 +0100 (BST) Message-ID: <4E46CF21.8090703@apache.org> Date: Sat, 13 Aug 2011 20:23:13 +0100 From: Steve Loughran User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.2; en-US; rv:1.9.2.17) Gecko/20110414 Thunderbird/3.1.10 MIME-Version: 1.0 To: general@hadoop.apache.org Subject: Re: Dedicated disk for operating system References: <044F0CA2-FC84-4720-A3DE-2D45329EC865@apache.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-HPL-MailScanner-Information: Please contact the ISP for more information X-MailScanner-ID: p7DJNISU026273 X-HPL-MailScanner: Found to be clean X-HPL-MailScanner-From: stevel@apache.org On 10/08/2011 20:31, Brian Bockelman wrote: > MTTF is a difficult number. Popular papers include: http://db.usenix.org/events/fast07/tech/schroeder/schroeder_html/index.html, http://labs.google.com/papers/disk_failures.pdf > > Ted is assuming a MTTF of 25kHours; I think that's overly pessimistic, although both papers indicate that MTTF is a crappy way to model disk lifetime. > see also [Gray05] http://research.microsoft.com/apps/pubs/default.aspx?id=64599