Getting started with OpenBSD means embracing a operating system built for security, correctness, and simplicity. The installation process reflects these priorities, guiding you through a methodical setup that prioritizes understanding over automation. This walkthrough focuses on a standard installation from CD or ISO, the most common and instructive method.
Preparing for OpenBSD Installation
Before the first prompt appears, preparation is essential. You must download the correct installation files, typically an ISO image for your specific architecture, usually `amd64` or `i386`. Verify the checksum of your downloaded file against the provided values to ensure the integrity and authenticity of the media. Create a bootable USB drive using a reliable tool like `dd` on Unix-like systems, which copies the ISO directly to the device, preserving the boot sector. Finally, consider disk layout beforehand, especially if dual-booting, as the installer handles partition alignment with precision but offers limited post-partitioning flexibility.
Booting the Installer
Insert your prepared media and power on the machine. At the boot prompt, which appears immediately on most platforms, you can simply press Enter for the default settings. The system will load the installation kernel and begin hardware detection. This stage is largely automatic, but you might need to pass specific hardware flags at the prompt if dealing with problematic legacy devices. Watch for console messages indicating disk detection and network controller initialization, as these confirm the system is ready for the core installer.
Navigating the Installation Steps
The installer is text-based, using a series of clear, sequential menus. Language selection comes first, followed immediately by keyboard layout configuration, where you should carefully choose the correct variant for your physical keyboard. The installer will then scan for supported network interfaces and attempt DHCP. If your network relies on static addressing, be prepared to abort DHCP and manually configure the IP address, subnet, and default gateway using the provided prompts before proceeding.
The critical disk layout step appears next. You can choose to auto-layout, which provides a secure and functional default partition scheme including swap and separate `/tmp` and `/var`. For advanced users, selecting `I` for manual layout opens the powerful `fdisk` and `disklabel` tools. Here you create the primary OpenBSD partition and then define the file systems, mount points, and swap space within it. This is where paths like `/`, `/home`, and `/usr` are decided, directly impacting future system management and security boundaries.
Package and Configuration Selection
After partitioning, the installer presents package choices. The `baseset` is mandatory, containing the core system. You should then select at least the `compilers` set if you plan to build software from ports later. The Xen set is only necessary for virtualized environments. Following package selection, you will configure system time, create a user account with sudo privileges—avoiding direct root login—and set the root password. These initial configurations solidify the security posture of your new system.
Installation concludes with the copying of files and installation of the boot loader. Upon completion, the system will prompt you to remove the installation media and reboot. When the machine restarts, you land at the login prompt. Log in with your new user account, verify network functionality, and then use `doas` to become root for final system updates. Running `pkg_add -u` and `pkg_add -Dai` ensures all installed packages are current, completing a robust and secure OpenBSD installation ready for daily use or specific server duties.
