Creating a bootable OpenBSD ISO

From Docupedia

It's actually very simple. Since the fine OpenBSD people ship a working bootable CD image all we have to do is grow the ISO to contain the i386 directory tree which contains the binary tarballs needed by the installer. If you want to do this for another version of OpenBSD or a different architecture just substitute 3.8 for your version and i386 for your architecture. There may not be a bootable ISO available for every architecture.

$ wget -r -np ftp://ftp.openbsd.org/pub/OpenBSD/3.8/i386
$ mv ftp.openbsd.org/pub/OpenBSD/3.8 .
$ cp 3.8/i386/cd38.iso OpenBSD-3.8.iso
$ growisofs -M OpenBSD-3.8.iso -R -iso-level 3 -graft-points 3.8=3.8
$ rm -rf 3.8 ftp.openbsd.org

Note: if you don't have growisofs installed you need the package: dvd+rw-tools have a look in your distro's package management system.

After you download the tree (at the time of this writing less than 160MB) the actual growing only takes a few seconds on any modern machine.

The resulting file, OpenBSD-3.8.iso can be burned with your favorite CD toasting program.

Update:

This has been used to make the 3.9, 4.0, 4.1, 4.2, 4.3, and 4.4 isos by Jeff Smith!. If that makes you feel warm and tingly.