From owner-freebsd-geom@FreeBSD.ORG Tue May 24 16:35:07 2011 Return-Path: Delivered-To: freebsd-geom@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D064F106564A for ; Tue, 24 May 2011 16:35:07 +0000 (UTC) (envelope-from xcllnt@mac.com) Received: from asmtpout026.mac.com (asmtpout026.mac.com [17.148.16.101]) by mx1.freebsd.org (Postfix) with ESMTP id B0D148FC17 for ; Tue, 24 May 2011 16:35:07 +0000 (UTC) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; CHARSET=US-ASCII Received: from sa-nc-common-178.static.jnpr.net (natint3.juniper.net [66.129.224.36]) by asmtp026.mac.com (Oracle Communications Messaging Exchange Server 7u4-20.01 64bit (built Nov 21 2010)) with ESMTPSA id <0LLP00MDPKQHV910@asmtp026.mac.com>; Tue, 24 May 2011 09:35:07 -0700 (PDT) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.4.6813,1.0.148,0.0.0000 definitions=2011-05-24_05:2011-05-24, 2011-05-24, 1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 ipscore=0 suspectscore=8 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx engine=6.0.2-1012030000 definitions=main-1105240099 From: Marcel Moolenaar In-reply-to: <4DDB5375.6050004@FreeBSD.org> Date: Tue, 24 May 2011 09:35:10 -0700 Message-id: References: <4DDA2F0B.2040203@yandex.ru> <9ED563AB-7B35-40F4-A33E-015317858401@bsdimp.com> <4DDB5375.6050004@FreeBSD.org> To: Andriy Gapon X-Mailer: Apple Mail (2.1084) Cc: "Andrey V. Elsukov" , Warner Losh , freebsd-geom@FreeBSD.org Subject: Re: [RFC] Remove requirement of alignment to track from MBR scheme X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 24 May 2011 16:35:07 -0000 On May 23, 2011, at 11:43 PM, Andriy Gapon wrote: > on 23/05/2011 20:38 Warner Losh said the following: >> >> On May 23, 2011, at 10:35 AM, Marcel Moolenaar wrote: >>> I think we've had enough rushed and ill thought-out changes going >>> in already and I can see that not aligning MBR partitions on a track >>> boundary is potentially perceived as a PITA violation. > > _PITA_ violation? :-) > As to POLA - yeah, I can see people getting astonished that finally FreeBSD got > its sh*t together and did the right thing, years after all other OSes (even > Winddows) had done it. :-) Well, I just initialized a USB stick on my Mac and I see that it still adheres to some notion of geometry: : ugen3.2: at usbus3 umass0: on usbus3 da0 at umass-sim0 bus 0 scbus0 target 0 lun 0 da0: Removable Direct Access SCSI-2 device da0: 1.000MB/s transfers da0: 499MB (1023484 512 byte sectors: 64H 32S/T 499C) GEOM: da0s1: EBR has non empty bootcode. GEOM: msdosfs/MAC: EBR has non empty bootcode. marcelm-server% gpart show da0 => 32 1023424 da0 MBR (499M) 32 31 - free - (15k) 63 1023372 1 fat32 (499M) 1023435 21 - free - (10k) gpart synthesized a 64 head, 32 sectors/track geometry, which is not the same as the 63 sectors/track that Mac synthesized. Yes, this demonstrates the bogosity of geometry, but it also shows that it still exists. All I'm saying: be careful. -- Marcel Moolenaar xcllnt@mac.com