Date: Tue, 30 Jul 2002 21:22:39 -0400 (EDT) From: Peter Leftwich <Hostmaster@Video2Video.Com> To: robert Backhaus <robbakfreebsd@yahoo.co.uk> Cc: Cherie & John Carri <cjcarri@earthlink.net>, FreeBSD LIST <FreeBSD-Questions@FreeBSD.Org> Subject: Re: Can FreeBSD make a hard drive unbootable by other OS's ? Message-ID: <20020730211435.A10245-100000@earl-grey.cloud9.net> In-Reply-To: <20020731005708.98499.qmail@web12903.mail.yahoo.com>
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On Tue, 30 Jul 2002, robert Backhaus wrote: > You can do anything with FreeBSD.... But you cannot undo anything (i.e. _everything_) with FreeBSD. *wahunnn* > Check out references on 'Dangerously Dedicated' disks. This looks promising - > http://www.pl.freebsd.org/FAQ/FAQ114.html Slices rock. But three things aren't clear at the above write-up: "The advantages of this mode are: FreeBSD owns the entire disk, no need to waste several fictitious `tracks' for just nothing but a 1980-aged simplistic partitioning model enforcing some artificial and now rather nonsensical constraints on how this partitioning needs to be done. These constraints often lead to what might be the biggest headaches for OS installations on PCs, geometry mismatch hassles resulting out of two different, redundant ways how to store the partitioning information in the fdisk table. See the chapter about Missing Operating System. In ``dangerously dedicated'' mode, the BSD bootstrap starts at sector 0, and this one is the only sector that always translates into the same C/H/S values, regardless of which `translation' your BIOS is using for your disk. Thus, you can also swap disks between systems/controllers that use a different translation scheme, without risking that they won't boot anymore." It isn't clear but they seem to be "selling" the reader on this version, even though the misnomer and scary name has the word dangerous in it. Er, that was kind of question one. "To return a ``dangerously dedicated'' disk for normal PC use, there are basically two options. The first is, you write enough NULL bytes over the MBR to make any subsequent installation believe this to be a blank disk. You can do this for example with `dd if=/dev/zero of=/dev/rsd0 count=15`" Here I am wondering why they say "to return a d.d.d. for normal PC use" - do they mean exclusively PC use? I would rest better if it was written from the angle of "here's why you may want to do x, y and z oh and here is how to -DO- x, y and z..." "Alternatively, the undocumented DOS ``feature'' `fdisk /mbr` will to install a new master boot record as well, thus clobbering the BSD bootstrap." Question 3, is this fdisk /mbr a DOS command or a FreeBSD command, or both? > It's nothing that a `ZapDisk' type utility won't fix. Ooh ooh ooh! What is ZapDisk? Is it like PartitionMagic for FreeBSDers?! -- Peter Leftwich President & Founder Video2Video Services Box 13692, La Jolla, CA, 92039 USA +1-413-403-9555 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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