From owner-freebsd-stable@FreeBSD.ORG Thu Nov 12 17:44:31 2009 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 297E1106566B for ; Thu, 12 Nov 2009 17:44:31 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from QMTA03.westchester.pa.mail.comcast.net (qmta03.westchester.pa.mail.comcast.net [76.96.62.32]) by mx1.freebsd.org (Postfix) with ESMTP id CA32C8FC08 for ; Thu, 12 Nov 2009 17:44:30 +0000 (UTC) Received: from OMTA03.westchester.pa.mail.comcast.net ([76.96.62.27]) by QMTA03.westchester.pa.mail.comcast.net with comcast id 4DH81d0070bG4ec53HkWlk; Thu, 12 Nov 2009 17:44:30 +0000 Received: from koitsu.dyndns.org ([98.248.46.159]) by OMTA03.westchester.pa.mail.comcast.net with comcast id 4HkV1d0023S48mS3PHkVJq; Thu, 12 Nov 2009 17:44:30 +0000 Received: by icarus.home.lan (Postfix, from userid 1000) id 487CB1E3035; Thu, 12 Nov 2009 09:44:28 -0800 (PST) Date: Thu, 12 Nov 2009 09:44:28 -0800 From: Jeremy Chadwick To: freebsd-stable@freebsd.org Message-ID: <20091112174428.GA24213@icarus.home.lan> References: <20091112103308.GA2536@hiMolde.no> <20091112115350.GA18542@icarus.home.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Subject: Re: SMART 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: Thu, 12 Nov 2009 17:44:31 -0000 On Thu, Nov 12, 2009 at 01:25:12PM +0100, Ivan Voras wrote: > Jeremy Chadwick wrote: > > >I can teach you how to decode/read SMART statistics correctly. > > > > Actually, it would be good if you taught more than him :) > > I've always wondered how important are each of the dozen or so > statistics and what indicates what... I started a write-up but after writing about 300 lines realised that if I continued the details would eventually be lost in the Sea of Information Chaos that is a mailing list. :-) I've gone over how to read SMART data 3 separate times in the past 2 months (at work, on a public forum, and in private mail), so this would be the 4th... I'll work on writing an actual HTML document to put up on my web site and will respond with the URL once I finish it. Sorry for the "yeah sure I can help you read this data" response followed by what will probably be labelled as an excuse by some. Admittedly reading the output is pretty simple, but "getting familiar" with what the output looks like (on a per-vendor basis) takes exposure to all sorts of drives, ditto with F/W bugs and so on. In general though, don't let anyone tell you SMART is worthless. The "overall health assessment" status is generally worthless, but the per-attribute data is of great use. Don't let anyone tell you the weighted/adjusted values (VALUE/WORST/THRESH) are useless either; in some cases they're all you can safely rely on. Don't damn SMART when it's actually the manufacturers which need to be spanked for setting such unreasonable health failure thresholds. -- | Jeremy Chadwick jdc@parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |