From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [ANNOUNCE] util-linux-ng v2.17 (stable) Date: Mon, 11 Jan 2010 08:52:56 -0800 Message-ID: <4B4B5768.2040005@zytor.com> References: <20100108093302.GS1969@nb.net.home> <4B47A713.9060405@zytor.com> <20100111140255.GA1416@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Karel Zak , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, util-linux-ng@vger.kernel.org To: Pavel Machek Return-path: Received: from terminus.zytor.com ([198.137.202.10]:47173 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751500Ab0AKQxa (ORCPT ); Mon, 11 Jan 2010 11:53:30 -0500 In-Reply-To: <20100111140255.GA1416@ucw.cz> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 01/11/2010 06:05 AM, Pavel Machek wrote: > On Fri 2010-01-08 13:43:47, H. Peter Anvin wrote: >> On 01/08/2010 01:33 AM, Karel Zak wrote: >>> >>> fdisk: >>> - the fdisk command aligns newly created partitions to minimum_io_size >>> boundary ("minimum_io_size" is physical sector size or stripe chunk >>> size on RAIDs). >>> >>> - the fdisk command supports disks with alignment_offset now. >>> >> >> I think we should align, by default, much more aggressively than that -- >> because frequently we just don't know what the real physical alignment >> is (think of flash media, which uses large erase blocks underneath.) > > Flash has special mapping layer, and does not care (SD/MMC), or is a > raw nand and can't be used as block device (smartmedia). > Uhm, that's just plain wrong. It doesn't matter if there is a "special mapping layer" -- if you're crossing multiple erase blocks you're still having more churn in your flash translation layer, with more wear on the device, and lower performance than if you didn't. -hpa