This chapter covers different ways to use OpenBSD to customize itself, as well as how to install OpenBSD in nonstandard situations and debug problems with your system. The first task we’ll address is diskless installation. Diskless systems are usually used to install OpenBSD without attaching any installation media, but they can also be used to run a system without a hard drive. Next, we’ll create a USB flash drive for use as OpenBSD installation media. Finally, we’ll cover various ways to customize the OpenBSD installation and upgrade processes.

All of these tasks assume that you already have an OpenBSD machine running the version you want to customize. You can accomplish some of these tasks using a virtual machine, as long as the virtual machine software has the necessary support. Because virtualization is such a common choice, let’s tackle it first.