1NOTE: If you wish to install OpenBSD on your whole disk, i.e. you do 2not want DOS or any other operating system to reside on your hard 3disk, you can skip this section and go on to the section that 4describes installation, below. If you're upgrading your system from a 5previous release of OpenBSD, you should have proceeded directly to the 6section about upgrading; you need none of the information presented 7here. 8 9First and foremost, before beginning the installation process, MAKE 10SURE YOU HAVE A RELIABLE BACKUP of any data on your hard disk that you 11wish to keep. Repartitioning your hard disk is an excellent way to 12destroy important data. 13 14Second, if you are using a disk controller which supports disk geometry 15translation, be sure to use the same parameters for OpenBSD as for DOS 16or the other operating systems installed on your disk. If you do not, 17it will be much harder to make OpenBSD properly coexist with them. 18Utilities exist which will print out the disk geometry which DOS sees; 19some versions of DOS "fdisk" also do this. If you have an "EIDE" hard 20disk, DOS and OpenBSD probably won't see the same geometry, and you must 21be careful to find out the DOS geometry and tell OpenBSD about it during 22the installation. 23 24Third (but related to the second point above), if you are using a hard 25disk with more sectors than DOS or your controller's BIOS supports without 26some kind of software translation utility or other kludge, you MUST 27BE SURE that all partitions which you want to boot from must start and end 28below cylinder 1024 by the BIOS's idea of the disk, and that all DOS 29partitions MUST EXIST ENTIRELY BELOW cylinder 1024, or you will either not 30be able to boot OpenBSD, not be able to boot DOS, or you may experience 31data loss or filesystem corruption. Be sure you aren't using geometry 32translation that you don't know about, but that the DOS "fdisk" program 33does! 34 35Fourth, use the other operating system's "fdisk" program or partition 36editor to create at least one of the partitions to be used for that 37operating system. If that operating system is already set up to use the 38entire disk, you will have to back it up, remove and recreate a smaller 39partition for it, and then restore the data from that partition. You do 40not have to create an OpenBSD partition at this time, the OpenBSD install- 41ation will give you an opportunity to create the partition needed for 42OpenBSD. 43 44Finally, do whatever is necessary to restore order to the partition 45you took space away from. If it was a DOS partition, you probably 46will need to use "format" to create a new file system on it, and then 47restore your important files from your backups. Other operating 48systems will have different needs; most will need to reformat the 49partition, and if it was their "main" partition, will probably need 50to be reinstalled. 51 52Once you've backed all your data up, there is a tool called fips 2.0 53that can shrink your DOS/Windows/Windows95 partition to make room for 54OpenBSD. It is included in the i386 tools area of this distribution as 55a convenience. It is strongly advised that you read its documentation 56and understand the consequences of your actions before using it. In some 57cases, defragmenting your disk and running fips may be much faster than 58reinstalling your DOS partitition from the backup. 59 60Your hard disk is now prepared to have OpenBSD installed on it, and 61you should proceed with the installation instructions. 62