Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 3 Jul 2002 04:14:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 3 Jul 2002 04:14:47 -0400 Received: from d12lmsgate-2.de.ibm.com ([195.212.91.200]:35303 "EHLO d12lmsgate-2.de.ibm.com") by vger.kernel.org with ESMTP id convert rfc822-to-8bit; Wed, 3 Jul 2002 04:14:47 -0400 Importance: Normal Sensitivity: Subject: Re: hd_geometry question. To: Andries Brouwer Cc: linux-kernel@vger.kernel.org X-Mailer: Lotus Notes Release 5.0.8 June 18, 2001 Message-ID: From: "Martin Schwidefsky" Date: Wed, 3 Jul 2002 10:13:19 +0200 X-MIMETrack: Serialize by Router on D12ML016/12/M/IBM(Release 5.0.9a |January 7, 2002) at 03/07/2002 10:17:06 MIME-Version: 1.0 Content-type: text/plain; charset=iso-8859-1 Content-transfer-encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1258 Lines: 31 >> Just to make sure I got that right, HDIO_GETGEO delivers a FAKE geometry >> based on the assumption that the sector size is 512 bytes ? > >I am tempted to just answer "yes". >You capitalize FAKE, as if that is an interesting and important part. >But non-fake geometries do not exist. Let me give a somewhat more >explicit answer. Thanks for the long answer, it helped me to understand the situation. Our problem is that we do have a REAL geometry for the dasd disks on a s/390. And for the old dasd driver in the 2.4 series HDIO_GETGEO delivers the real geometry of the disk measured in physical blocks which is not necessarily 512 bytes. Most often it is 4096 bytes. The problem now is that if geo.start is REQUIRED to be measured in 512 byte blocks we have to incompatibly change the HDIO_GETGEO ioctl. Not nice. blue skies, Martin Linux/390 Design & Development, IBM Deutschland Entwicklung GmbH Sch?naicherstr. 220, D-71032 B?blingen, Telefon: 49 - (0)7031 - 16-2247 E-Mail: schwidefsky@de.ibm.com - 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/