From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id o6QA4BkJ112986 for ; Mon, 26 Jul 2010 05:04:11 -0500 Received: from smtp4-g21.free.fr (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 07AC8471319 for ; Mon, 26 Jul 2010 03:07:13 -0700 (PDT) Received: from smtp4-g21.free.fr (smtp4-g21.free.fr [212.27.42.4]) by cuda.sgi.com with ESMTP id 4hZwepoj7TfD4286 for ; Mon, 26 Jul 2010 03:07:13 -0700 (PDT) Date: Mon, 26 Jul 2010 12:07:08 +0200 From: Emmanuel Florac Subject: Re: 4k drives: benefits and models? Message-ID: <20100726120708.53ac63e3@harpe.intellique.com> In-Reply-To: <19533.22251.225560.835077@tree.ty.sabi.co.uk> References: <20100726082141.GA8239@apartia.fr> <19533.22251.225560.835077@tree.ty.sabi.co.uk> Mime-Version: 1.0 List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Peter Grandi Cc: Linux XFS Le Mon, 26 Jul 2010 10:35:39 +0100 pg_xf2@xf2.for.sabi.co.UK (Peter Grandi) =E9crivait: > It is purely higher density. A longer physical sector means less > percentage of the disk is "wasted" on metadata. This benefits > the manufacturer mostly, so they can claim more capacity with > less cost (but more credibly than the far more slimy trick of > LCD manufacturers who are going to ever more extreme landscape > ratios to claim a longer diagonal with less pixels). > = It isn't actually that simple. By keeping the same metadata ratio, the largest correctable error goes up from 10 bytes to 80 bytes. That means taht the new drives should be much less prone to uncorrectable ECC errors, which are the real culprit with the previous generation of big drives (Seagate barracuda 1, 1.5 and 2TB are particularly terrible IMO). > From the user/filesystem point iof view it is not a positive > thing, but since the 4BSD FFS introduced 4KiB blocks (a very bad > idea) and intel and others followed throught with alrge 4KiB > pages that has been largely irrelevant. This was eons ago, I'm pretty sure we managed to live with it :) What was problematic back when disks drives were in the hundreds of megabytes isn't so much a problem when the smallest drives available (146 GB) are 1000 times bigger. Many filesystems use much bigger blocks on bigger filesystems, too (NTFS anyone? WS2003 can use 16, 32 or even 64 KB). -- = ------------------------------------------------------------------------ Emmanuel Florac | Direction technique | Intellique | | +33 1 78 94 84 02 ------------------------------------------------------------------------ _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs