From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263804AbTDIU6y (for ); Wed, 9 Apr 2003 16:58:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263812AbTDIU6y (for ); Wed, 9 Apr 2003 16:58:54 -0400 Received: from pc2-cwma1-4-cust86.swan.cable.ntl.com ([213.105.254.86]:17822 "EHLO lxorguk.ukuu.org.uk") by vger.kernel.org with ESMTP id S263804AbTDIU6x (for ); Wed, 9 Apr 2003 16:58:53 -0400 Subject: RE: questions regarding Journalling-FSes and w-cache reordering From: Alan Cox To: Linux Kernel Mailing List Cc: "'Oliver S.'" In-Reply-To: <785F348679A4D5119A0C009027DE33C102E0D0B1@mcoexc04.mlm.maxtor.com> References: <785F348679A4D5119A0C009027DE33C102E0D0B1@mcoexc04.mlm.maxtor.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Organization: Message-Id: <1049919134.10871.5.camel@dhcp22.swansea.linux.org.uk> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.2.2 (1.2.2-5) Date: 09 Apr 2003 21:12:16 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mer, 2003-04-09 at 20:52, Mudama, Eric wrote: > ATA hard drives are allowed to reorder/merge/etc their write caches if write > cache is enabled. With write caching enabled, there is no guarantee that > dirty data will be flushed in any specific order, nor does the ATA protocol > support any such ordering beyond the global flush cache command. To cheer people up further by the way, not all ATA drives support cache flush, some drives dont support write cache disable and others implement write/verify as write. So basically you can't do it.