From owner-freebsd-stable@FreeBSD.ORG Sun Aug 21 10:05:59 2011 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 85E6D106564A for ; Sun, 21 Aug 2011 10:05:59 +0000 (UTC) (envelope-from ma@dt.e-technik.uni-dortmund.de) Received: from krusty.dt.e-technik.tu-dortmund.de (krusty.dt.E-Technik.Uni-Dortmund.DE [129.217.163.1]) by mx1.freebsd.org (Postfix) with ESMTP id 47ACA8FC08 for ; Sun, 21 Aug 2011 10:05:59 +0000 (UTC) Received: from [192.168.0.4] (f055048121.adsl.alicedsl.de [78.55.48.121]) by mail.dt.e-technik.tu-dortmund.de (Postfix) with ESMTPSA id 27D629C2D3 for ; Sun, 21 Aug 2011 11:48:34 +0200 (CEST) Message-ID: <4E50D470.4090800@dt.e-technik.uni-dortmund.de> Date: Sun, 21 Aug 2011 11:48:32 +0200 From: Matthias Andree User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.18) Gecko/20110617 Mnenhy/0.8.3 Thunderbird/3.1.11 MIME-Version: 1.0 To: freebsd-stable@freebsd.org References: <1B4FC0D8-60E6-49DA-BC52-688052C4DA51@langille.org> <20110819232125.GA4965@icarus.home.lan> <20110820032438.GA21925@icarus.home.lan> <4774BC00-F32B-4BF4-A955-3728F885CAA1@langille.org> In-Reply-To: <4774BC00-F32B-4BF4-A955-3728F885CAA1@langille.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Subject: Re: bad sector in gmirror HDD X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 21 Aug 2011 10:05:59 -0000 Am 20.08.2011 19:34, schrieb Dan Langille: > This is an older system. I suspect insufficient ventilation. I'll look at getting > a new case fan, if not some HDD fans. The answer is quite simple, get new drives. They have gone for some 24000 hours, IOW, at least 3 years (assuming 24x7), and at around 50 °C, they're worn. After three years, at the slightest hitch, replace drives, before Something Bad[tm] happens. You'll get faster replacements anyhow :) On a related note, since this is about gmirror: Linux has a similar subsystem in place called the drive mapper (dm), with user-space tools mdadm. The whole rig (kernel + user space) supports various RAID levels through modules, the gmirror equivalent being raid1 -- and that module somewhat recently acquired an interesting *feature:* it can automatically rewrite broken sectors. Meaning that when it sees a read error on one drive, it will read the block from the intact other drive and re-write it on the faulty drive so that it gets reallocated (assuming nobody turned the drive's ARWE feature off). Perhaps that's a useful feature for gmirror, too. > 2848980992 bytes transferred in 127.128503 secs (22410246 bytes/sec) Eek, someone should fix dd to use proper units and not confuse seconds (s) with the secans function (sec). Anyways, that's pretty low by today's standards. My I/O speeds even on lowly Samsung 5400/min drives are in excess of 100 MBytes/s, and that's talking about drives made in 2009.