Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 2 Jul 2002 05:17:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 2 Jul 2002 05:17:32 -0400 Received: from d12lmsgate-2.de.ibm.com ([195.212.91.200]:20392 "EHLO d12lmsgate-2.de.ibm.com") by vger.kernel.org with ESMTP id ; Tue, 2 Jul 2002 05:17:31 -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: Tue, 2 Jul 2002 11:16:06 +0200 X-MIMETrack: Serialize by Router on D12ML016/12/M/IBM(Release 5.0.9a |January 7, 2002) at 02/07/2002 11:19:48 MIME-Version: 1.0 Content-type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1041 Lines: 26 >About a partition one wants to know start and length. >About a full disk one wants to know size, and perhaps a (fake) geometry. > >The vital partition data cannot depend on obscure hardware info. >So, the units used must be well-known. Earlier, everything was in >512-byte sectors, but there are a few places where that is inconvenient >or unnatural, and now that one has more than 2^32 sectors and 64 bits >are needed anyway, things are measured in bytes. > >That the start field comes with the HDIO_GETGEO ioctl and the size with >the BLKGETSIZE ioctl is due to history. Both are given in 512-byte sectors. >BLKGETSIZE64 gives bytes. 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 ? blue skies, Martin - 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/