NOTE: If you wish to install OpenBSD on your whole disk, i.e. you do
not want DOS or any other operating system to reside on your hard
disk, you can skip this section and go on to the section that
describes installation, below.  If you're upgrading your system from a
previous release of OpenBSD, you should have proceeded directly to the
section about upgrading; you need none of the information presented
here.

First and foremost, before beginning the installation process, MAKE
SURE YOU HAVE A RELIABLE BACKUP of any data on your hard disk that you
wish to keep.  Repartitioning your hard disk is an excellent way to
destroy important data.

Second, if you are using a disk controller which supports disk geometry
translation, be sure to use the same parameters for OpenBSD as for any
other operating systems installed on the disk.  If you do not, it
will be much harder to make OpenBSD properly coexist with them.  Most
operating systems have utilities that print out the disk geometry they
use; often "fdisk" (or its equivalent) will do this.

Third (but related to the second point above), if you are using a hard
disk with more cylinders than are supported by the other operating
systems or the BIOS, you MUST be sure that all boot partitions start and
end within the area supported by both the BIOS and the OS in question.

The OpenBSD root partition must also reside completely within the BIOS
supported part of the hard disk -- this could typically be 504MB, 2GB,
8GB or 128GB, depending upon the age of the machine and its BIOS. The
rest of the OpenBSD partitions can be anywhere that hardware supports.

Fourth, use the other operating system's "fdisk" program or partition
editor to create at least one of the partitions to be used for that
operating system.  If that operating system is already set up to use the
entire disk, you will have to back it up, remove and recreate a smaller
partition for it, and then restore the data from that partition.  You do
not have to create an OpenBSD partition at this time; the OpenBSD install-
ation will give you an opportunity to create the partition needed for
OpenBSD.

Finally, do whatever is necessary to restore order to the partition
you took space away from.  If it was a DOS partition, you probably
will need to use "format" to create a new file system on it, and then
restore your important files from your backups.  Other operating
systems will have different needs; most will need to reformat the
partition, and if it was their "main" partition, will probably need
to be reinstalled.

Once you've backed all your data up, there is a tool called fips 2.0
that can shrink your FAT-based DOS/Windows partition to make room for
OpenBSD.  It is included in the MACHINE tools area of this distribution as
a convenience.  It is strongly advised that you read its documentation
and understand the consequences of your actions before using it.  In some
cases, defragmenting your disk and running fips may be much faster than
reinstalling your DOS partition from the backup.

Windows 7 (and possibly Vista) can resize their own system partition, which
is usually NTFS. In the control panel, search for "partition": this will lead
you to the system administration tool. Then right click on the partition you
wish to shrink.  You may have to fiddle with the swap file, because it's
unmoveable, and you might not be able to shrink the partition as much as you
would wish.

Your hard disk is now prepared to have OpenBSD installed on it, and
you should proceed with the installation instructions.