From owner-freebsd-hardware Mon Aug 5 02:35:32 1996 Return-Path: owner-hardware Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id CAA04907 for hardware-outgoing; Mon, 5 Aug 1996 02:35:32 -0700 (PDT) Received: from godzilla.zeta.org.au (godzilla.zeta.org.au [203.2.228.19]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id CAA04902 for ; Mon, 5 Aug 1996 02:35:26 -0700 (PDT) Received: (from bde@localhost) by godzilla.zeta.org.au (8.6.12/8.6.9) id TAA09191; Mon, 5 Aug 1996 19:27:44 +1000 Date: Mon, 5 Aug 1996 19:27:44 +1000 From: Bruce Evans Message-Id: <199608050927.TAA09191@godzilla.zeta.org.au> To: BRETT_GLASS@ccgate.infoworld.com, rgrimes@GndRsh.aac.dev.com Subject: Re: Mapped geometry vs. Actual Cc: hardware@freebsd.org, msmith@atrad.adelaide.edu.au, randy@zyzzyva.com Sender: owner-hardware@freebsd.org X-Loop: FreeBSD.org Precedence: bulk >> It seems as if it also tries to force disk slices to >> cylinder boundaries -- which is silly on ZBR drives or when sector mapping >> is done. >That is to maintain compatibility with other operating systems, if you don't >do this some other OS's fdisk may try to ``fix'' your MBR partition table >for you and make a royal mess of things instead. Sysinstall may do this, but fdisk(8) lets you put the slices wherever you want. >Cylinder bondaries alignment must be retained if you ever let anything >bug FreeBSD /sbin/fdisk near your disk drive. Wrong. The primary DOS partition is normally NOT aligned to a cylinder boundary. It normally starts 1 track after a cylinder boundary. I used to start it 1 sector after a cylinder boundary. DOS 3.2 had no problems with this. Logical drives within extended partitions are normally NOT aligned to a cylinder boundary. They normally start 1 track after a cylinder boundary (1 track after the start of an extended partition which normally does start on a cylinder boundary). Bruce