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Re: i386 mbr problem, again

Tim Newsham wrote:
> > Try booting a Windows rescue diskette and running
> >
> > a:> fdisk /mbr
> This fixed my problem.
> My apologies for the FAQ.  (Actually I looked and couldnt
> find it just now, Where exactly is this item mentioned?)
> Does this mean that before OpenBSD can be installed
> on a system, there must already be a DOS MBR created
> on the drive?  If so, this seems braindead.  Not
> everyone installs OpenBSD/x86 over a former windows
> installation.


In my experience, if you take a never-before-used drive, and do an
OpenBSD install on it on a machine that fully recognizes the drive
geometry, OpenBSD installs (and later boots!) just fine.

It seems to be when the drive has been used for other things in the
past, or on machines which treat the drive geometry differently,
things don't work quite right, and the (DOS) 'fdisk /mbr' fixes the
problem.  Installing over an alternative OS actually may be related to
the problem.

It is *possible* that if you do a 'reinit', it might resolve this
problem, but unfortunately, that clobbers any other partitions on the
disk, so it is an install-time only option.  In any case where I
possibly can, I use this command before doing my desired disk layout,
and I haven't had a problem like this in quite some time.  Now,
drawing a firm connection between my 'reinit's and my lack of problems
is improper diagnostic process, but it is suggestive.

As for where it is documented: in the archives, though if you punch
the message in too literally, the search engines tend to choke on the
punctuation.  As this is an _install_ question, the archives you would
want to check would be the misc@ list, not the Tech@ list (please
re-read all of http://www.openbsd.org/mail.html).  This little tip is
not in the FAQs, not quite sure why...it is much easier, esp. for new
users than the proposed solutions, and many have reported much greater
success.  It DOES have the disadvantage of requiring commercial
software to implement, and that is very possibly why it is NOT in the