From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763353AbXGFOkd (ORCPT ); Fri, 6 Jul 2007 10:40:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755917AbXGFOkX (ORCPT ); Fri, 6 Jul 2007 10:40:23 -0400 Received: from shawidc-mo1.cg.shawcable.net ([24.71.223.10]:38670 "EHLO pd2mo1so.prod.shaw.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754655AbXGFOkV (ORCPT ); Fri, 6 Jul 2007 10:40:21 -0400 Date: Fri, 06 Jul 2007 08:39:28 -0600 From: Robert Hancock Subject: Re: PATA-disk named sda In-reply-to: To: Christoph Pleger Cc: linux-kernel@vger.kernel.org Message-id: <468E5420.7090605@shaw.ca> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit References: User-Agent: Thunderbird 2.0.0.4 (Windows/20070604) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Christoph Pleger wrote: > Hello, > >>> In the newest Ubuntu Release, my PATA-disk is called sda instead of >>> hda. Is that a general feature in newer kernel versions or is it a >>> special feature in Ubuntu? >> General. SATA and now PATA drives map onto the /dev/sd range as do >> SCSI, USB etc > > It seems to be not that simple, at least not if both the old IDE > interface and the new libata interface are enabled as modules: In my > Ubuntu system, I created two kernel packages (from the same kernel > source and with the same configuration) and installed them. Afterwards, > I re-created the initial ramdisks, one with the Ubuntu feisty utilities > and one with Debian etch utilities. So, I had the same kernel with > different ramdisks. With the Ubuntu ramdisk, my harddrive was named sda, > but with the Debian ramdisk, it was named hda. > > So, the name of the drive can depend on something which happens in the > ramdisk environment. Does anybody know what that is? And is there a > kernel command line parameter which restores the old behaviour? > > And what about hdparm (setting 32bit I/O and multi-sector mode)? Suren > wrote that 32bit I/O makes no sense when using DMA. Maybe that's right, > but it does not correspond with my experiences. At least, I have the > "feeling" that my IDE disks work much faster since I enabled 32bit > support (DMA already was on before). No, it has absolutely no effect in DMA mode. Currently the DMA, multi-sector mode, etc. are not controllable with hdparm with libata. libata is designed to use the fastest settings possible by default. In a lot of cases this messing with hdparm was only needed because of stupidity with the old IDE code (like DMA not being automatically enabled if the low-level driver was built modular). -- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.com/