Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756500AbZADXbS (ORCPT ); Sun, 4 Jan 2009 18:31:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751616AbZADXbF (ORCPT ); Sun, 4 Jan 2009 18:31:05 -0500 Received: from thunk.org ([69.25.196.29]:49102 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751531AbZADXbD (ORCPT ); Sun, 4 Jan 2009 18:31:03 -0500 Date: Sun, 4 Jan 2009 18:30:52 -0500 From: Theodore Tso To: Pavel Machek Cc: Sitsofe Wheeler , Duane Griffin , Valdis.Kletnieks@vt.edu, Martin =?utf-8?Q?MOKREJ=C5=A0?= , kernel list , Andrew Morton , mtk.manpages@gmail.com, rdunlap@xenotime.net, linux-doc@vger.kernel.org Subject: Re: document ext3 requirements Message-ID: <20090104233052.GG22958@mit.edu> Mail-Followup-To: Theodore Tso , Pavel Machek , Sitsofe Wheeler , Duane Griffin , Valdis.Kletnieks@vt.edu, Martin =?utf-8?Q?MOKREJ=C5=A0?= , kernel list , Andrew Morton , mtk.manpages@gmail.com, rdunlap@xenotime.net, linux-doc@vger.kernel.org References: <49610911.8000204@yahoo.com> <20090104193141.GA22958@mit.edu> <20090104224052.GE1913@elf.ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090104224052.GE1913@elf.ucw.cz> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@mit.edu X-SA-Exim-Scanned: No (on thunker.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1307 Lines: 27 On Sun, Jan 04, 2009 at 11:40:52PM +0100, Pavel Machek wrote: > Not neccessarily. > > If I have a bit of precious data and lot of junk on the card, I want > to copy out the precious data before the card dies. Reading the whole > media may just take too long. > > That's probably very true for rotating harddrives after headcrash... For a small amount data, maybe; but the number of seeks is often far more destructive than the amount of time the disk is spinning. And in practice, what generally happens is the user starts looking around to make sure there wasn't anything else on the disk worth saving, and now data is getting copied off based on human reaction time. So that's why I normally advise users that doing a full image copy of the disk is much better than, say, "cp -r /home/luser /backup", or cd'ing around a filesystem hierarchy and trying to save files one by one. Note also that with SD cards, reading is generally non-destructive and the time it takes to copy off say, 32 GB really isn't that long. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/