From owner-freebsd-questions@freebsd.org Fri Jul 3 02:28:55 2015 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 43B82993DAA for ; Fri, 3 Jul 2015 02:28:55 +0000 (UTC) (envelope-from zarniwhoop@ntlworld.com) Received: from know-smtprelay-omc-7.server.virginmedia.net (know-smtprelay-omc-7.server.virginmedia.net [80.0.253.71]) by mx1.freebsd.org (Postfix) with ESMTP id B023A1C01 for ; Fri, 3 Jul 2015 02:28:53 +0000 (UTC) (envelope-from zarniwhoop@ntlworld.com) Received: from localhost.localdomain ([81.106.150.188]) by know-smtprelay-7-imp with bizsmtp id neTk1q01m4481jl01eTknd; Fri, 03 Jul 2015 03:27:44 +0100 X-Originating-IP: [81.106.150.188] X-Spam: 0 X-Authority: v=2.1 cv=JuUM15MC c=1 sm=1 tr=0 a=DGj713NdaxKrsjjgQne7PA==:117 a=DGj713NdaxKrsjjgQne7PA==:17 a=NLZqzBF-AAAA:8 a=yEdEr6MRgwAA:10 a=IkcTkHD0fZMA:10 a=zOBTXjUuO1YA:10 a=j9nDSXTfFJhM8NtkZUAA:9 a=i89wmMABHIe9ljUC:21 a=8TqA9ShfTb8dm06Q:21 a=QEXdDO2ut3YA:10 Received: by localhost.localdomain (Postfix, from userid 500) id 0123C88614; Fri, 3 Jul 2015 03:27:43 +0100 (BST) Date: Fri, 3 Jul 2015 03:27:43 +0100 From: Ken Moffat To: freebsd-questions@freebsd.org Subject: Re: slightly off topic: SMART error values for seagate drives Message-ID: <20150703022743.GA5293@milliways> References: <5595EE90.5050105@sneakertech.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline X-Clacks-Overhead: GNU Terry Pratchett Content-Transfer-Encoding: 8bit In-Reply-To: <5595EE90.5050105@sneakertech.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Jul 2015 02:28:55 -0000 On Thu, Jul 02, 2015 at 10:08:16PM -0400, Quartz wrote: > Is anyone familiar with exactly how the raw_read_error_rate, > reallocated_sector_count, seek_error_rate, hardware_crc_recovered, and > udma_crc_error_count values work for seagate drives? > > AFAIK at least some of these fields list the (average?) number of sectors > between errors, and thus a higher raw value is better ...I think. I have > several apparently healthy seagate drives with very high rrer/ser/her raw > values that seem to support this. > > I recently took an older disk out of storage, and as part of my system > building procedure I always run a few tests over it before putting it back > into service. Initially it also had high rrer/ser/her raw values. It failed > a SMART extended test at about 40% remaining with a read failure, and the > udma_crc_error_count jumped from 0 to 5. I know sometimes this can be just > transient flakiness, so I just zeroed out the entire drive with dd to > exercise all the sectors and force any remappings. Now, the > reallocated_sector_count bumped up to 9, and the raw_read_error_rate and > hardware_crc_recovered fields plummeted from the millions down to like 13 > ...and have since slowly risen to the 40's. > > I can't tell what's going on with SMART values anymore, every vendor does > things differently and nothing's ever documented. Is having the reallocated > sectors value go up still a bad thing, or did seagate change what this > means? Why did the read error rate and crc recovered fields bottom out, but > the seek error rate is still in the clouds? Is this drive failing, or fine, > or what? > Based on a small number of low-end consumer-level desktop machines, my experience is that an increasing reallocated sector count is a bad sign. In theory, we ought to be able to run with a number of reallocated sectors - but I only really notice when sectors become (temporarily) inaccessible. Generally, you get what you pay for - and the sorts of drives I buy are built down to a price. ĸen -- This one goes up to eleven!