From owner-freebsd-current Mon Dec 10 3:50:16 2001 Delivered-To: freebsd-current@freebsd.org Received: from salmon.maths.tcd.ie (salmon.maths.tcd.ie [134.226.81.11]) by hub.freebsd.org (Postfix) with SMTP id A139C37B416 for ; Mon, 10 Dec 2001 03:50:13 -0800 (PST) Received: from walton.maths.tcd.ie by salmon.maths.tcd.ie with SMTP id ; 10 Dec 2001 11:50:11 +0000 (GMT) To: Peter Wemm Cc: Joerg Wunsch , freebsd-current@FreeBSD.ORG Subject: Re: cvs commit: src/sys/kern subr_diskmbr.c In-Reply-To: Your message of "Sun, 09 Dec 2001 16:43:50 PST." <20011210004350.6703C3810@overcee.netplex.com.au> Date: Mon, 10 Dec 2001 11:50:10 +0000 From: Ian Dowse Message-ID: <200112101150.aa33241@salmon.maths.tcd.ie> Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG In message <20011210004350.6703C3810@overcee.netplex.com.au>, Peter Wemm writes : >The problem is, that you **are** using fdisk tables, you have no choice. >DD mode included a *broken* fdisk table that specified an illegal geometry. ... >This is why it is called dangerous. BTW, I presume you are aware of the way sysinstall creates DD MBRs; it does not use the 50000 sector slice 4 method, but sets up slice 1 to cover the entire disk including the MBR, with c/h/s entries corresponding to the real start and end of the disk, e.g: cylinders=3544 heads=191 sectors/track=53 (10123 blks/cyl) ... The data for partition 1 is: sysid 165,(FreeBSD/NetBSD/386BSD) start 0, size 35885168 (17522 Meg), flag 80 (active) beg: cyl 0/ head 0/ sector 1; end: cyl 1023/ head 190/ sector 53 The data for partition 2 is: The data for partition 3 is: The data for partition 4 is: Otherwise the disk layout is the same as disklabel's DD. I suspect that this approach is much less illegal than disklabel's MBRs although I do remember seeing a HP PC that disliked it. I wonder if a reasonable compromise is to make disklabel use this system for DD disks instead of the bogus 50000 sector slice? Obviously, it should also somehow not install a partition table unless boot1 is being used as the MBR, and the fdisk -I method should be preferred. Ian To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message