Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932389AbYJKRw3 (ORCPT ); Sat, 11 Oct 2008 13:52:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761916AbYJKRwQ (ORCPT ); Sat, 11 Oct 2008 13:52:16 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:58780 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758211AbYJKRwP (ORCPT ); Sat, 11 Oct 2008 13:52:15 -0400 Date: Sat, 11 Oct 2008 18:51:57 +0100 From: Alan Cox To: Pavel Machek Cc: Chris Snook , Stefan Monnier , linux-kernel@vger.kernel.org Subject: Re: Filesystem for block devices using flash storage? Message-ID: <20081011185157.478ea357@lxorguk.ukuu.org.uk> In-Reply-To: <20081011143552.GA1556@ucw.cz> References: <48ED1D62.8080100@redhat.com> <20081011143552.GA1556@ucw.cz> X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.12; x86_64-redhat-linux-gnu) Organization: Red Hat UK Cyf., Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, Y Deyrnas Gyfunol. Cofrestrwyd yng Nghymru a Lloegr o'r rhif cofrestru 3798903 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 820 Lines: 20 > > Writes to magnetic disks are functionally atomic at the sector level. No they are not. > I don't think ext3 is safe w.r.t. whole eraseblocks disappearing. So > if you write data 'nearby' root directory and power fails, bye bye > filesystem, and journal will not help. You have similar problems on rotating media. A write to a block can corrupt other blocks adjacent to the block you write, and on the latest disks the physical block size can be greater than the logical one so unless you laid your partitions out right you have read-modify-write cycles goin on. Alan -- 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/