OpenBSD has a claim of being the most secure Operating System out-of-the-box. The problem is the installation is not very intuitive. Here I will be guiding you through a standard installation of OpenBSD 3.5 and this guide assumes you have a basic i386 PC to work with and will be using your entire disk for OpenBSD. Nothing fancy or unordinary. For this guide, I used a 3.0 gig harddrive.
- An OpenBSD ISO burned on a CD or grab the boot floppy images.
Section A — Booting
Once the system has booted, press ‘i’ for install. Choose the default vt220 terminal type. No need to select a keyboard encoding table if you are using a plain keyboard.
Proceed with install if your data is backed up or you are on a fresh install.
Section B — Partitioning
Chose the disk you will be working with. Mine was wd0 and I opted to use the entire disk for the OS. Now we need to partition the disk to enable all available security features of OpenBSD.
The partitioning tool of OpenBSD isn’t very intuitive or easy. It can be quite overwhelming at first. What I did was deleted the default partition ‘a’ by
> d a
Then I created the following partitions: /, swap, /tmp, /var, /usr, and /home using the default filesystem type of 4.2BSD. All you have to do is start the partition creation menu process for each partition by using the following as a guideline (text in  is the default value):
> a partition: [a] offset:  size:  256m Rounding to nearest cylinder: 524097 FS type: [4.2BSD] mount point: [/] > a partition: [b] offset:  size:  384m Rounding to nearest cylinder: 786240 FS type: [swap] > a partition: [d] offset:  size:  256m Rounding to nearest cylinder: 524160 FS type: [4.2BSD] mount point: [none] /tmp > a partition: [e] offset:  size:  256m Rounding to nearest cylinder: 524160 FS type: [4.2BSD] mount point: [none] /var > a partition: [f] offset:  size:  1400m Rounding to nearest cylinder: 2866752 FS type: [4.2BSD] mount point: [none] /usr > a partition: [g] offset:  size:  FS type: [4.2BSD] mount point: [none] /home >
Now we have to write the changes, save, and quit the partitioning tool. We will then be prompted to set the mount points for wd0x like the following:
> w > q No label changes. The root filesystem will be mounted on wd0a. wd0b will be used for swap space. Mount point for wd0d (size=262080k)? (or 'none' or 'done') [/tmp] Mount point for wd0e (size=262080k)? (or 'none' or 'done') [/var] Mount point for wd0f (size=1433376k)? (or 'none' or 'done') [/usr] Mount point for wd0g (size=532224k)? (or 'none' or 'done') [/home] Mount point for wd0d (size=262080k)? (or 'none' or 'done') [/tmp] done No more disks to initialize.
You should now see your partitions and mount points for verification. Next you will be prompted to create the filesystem on each partition. Of course, choose ‘yes.’
Section C — Networking
Now it is time to give your OpenBSD box its hostname and network. You should be familiar with setting up the network at install on other BSD boxes or Linux boxes. This doesn’t ask any different information.
Section D — Installation Sets
Now that your network is set up, you have to enter your root password. Once that is set, you have to tell the installer where to find the install sets. Because we don’t have the purchased cds, we have to install the OS over ftp or http. So, select either ‘f’ or ‘h’ and enter in the server you will be connecting to. You may have the same trouble as I did with the ftp servers so I used http://openbsd.secsup.org and the directory for the sets were in 3.5/i386.
Once it finds the server, it will list the sets to select from. You can choose what sets you want by typing their name. I just did the default, less the games. For a complete description of the files, check out http://openbsd.org/faq/faq4.html#FilesNeeded.
When all files are downloaded, type ‘done’ and then of course answer the question about sshd and your expectations on running X Server. Then set your timezone.
When prompted to do so, halt the system and reboot to your newly installed OpenBSD system!