From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263850AbUHNWvo (ORCPT ); Sat, 14 Aug 2004 18:51:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266249AbUHNWvo (ORCPT ); Sat, 14 Aug 2004 18:51:44 -0400 Received: from the-village.bc.nu ([81.2.110.252]:50139 "EHLO localhost.localdomain") by vger.kernel.org with ESMTP id S263850AbUHNWvn (ORCPT ); Sat, 14 Aug 2004 18:51:43 -0400 Subject: Re: Linux SATA RAID FAQ From: Alan Cox To: Jeff Garzik Cc: Bernd Eckenfels , Linux Kernel Mailing List In-Reply-To: <411BA940.5000300@pobox.com> References: <1092315392.21994.52.camel@localhost.localdomain> <411BA7A1.403@pobox.com> <411BA940.5000300@pobox.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1092520163.27405.11.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Sat, 14 Aug 2004 22:49:24 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Iau, 2004-08-12 at 18:30, Jeff Garzik wrote: > > The SX4 has an on-board DIMM (128M - 2G), through which all data _must_ > > pass. The data transfer between host and on-board DIMM is a separate > > DMA engine and separate interrupt event from the four ATA DMA engines > > (one per SATA port). There are several possibilities that are worth > > exploring on this card: > > > > * Caching Is it battery backed ? If it is battery backed then its useful, if not then it becomes less useful although not always. The i2o drivers have some ioctls so you can turn on writeback caching even without battery backup. While this is suicidal for filesytems its just great for swap..