From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: util-linux-owner@vger.kernel.org Received: from caiajhbdcagg.dreamhost.com ([208.97.132.66]:35492 "EHLO homiemail-a5.g.dreamhost.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751773Ab2GZK3p (ORCPT ); Thu, 26 Jul 2012 06:29:45 -0400 Subject: Re: fdisk geometry From: Davidlohr Bueso Reply-To: dave@gnu.org To: Karel Zak Cc: John Lane , util-linux@vger.kernel.org In-Reply-To: <20120726095752.GD17589@x2.net.home> References: <50109E8D.2000702@jelmail.com> <1343294980.2609.4.camel@offbook> <20120726095752.GD17589@x2.net.home> Content-Type: text/plain; charset="UTF-8" Date: Thu, 26 Jul 2012 12:29:41 +0200 Message-ID: <1343298581.2609.8.camel@offbook> Mime-Version: 1.0 Sender: util-linux-owner@vger.kernel.org List-ID: On Thu, 2012-07-26 at 11:57 +0200, Karel Zak wrote: > On Thu, Jul 26, 2012 at 11:29:40AM +0200, Davidlohr Bueso wrote: > > > (a) where fdisk gets the information about the geometry from in this > > > specific case? > > > > fdisk gets the information from (i) user input, (ii) what the > > kernel/bios thinks the geometry is, with the HDIO_GETGEO ioctl and (iii) > > by inferring it from the partition table geometry. > > BTW, does it make any sense to read the geometry from partition table > if the partition table has been aligned according to the device topology > (for example 1MiB offset and grain)? Hmm not really, no. In any case we got rid of the pt geometry, __discover_system_geometry() only gets the info from the kernel. > > > fdisk even bother displaying a geometry any more ? Doesn't it just serve > > > to confuse? > > IMHO for non-DOS compatible mode it would be better to ignore PT > geometry (read only info from kernel to have "some" values) and > don't display geometry in the default output, because it's completely > irrelevant. > > The same we can do with -S -C -H options -- it would be better to > print a warning if the options are specified for non-DOS mode. > I agree. > I still see on many places suggestions like "use -S -H to align your > flash disk" or so... all this is legacy. > > Karel >