Categories: Fundamentals Network DNS Self-Hosting
Understand the DNS hierarchy, resolver configuration, local DNS servers, and alternative DNS strategies for privacy-conscious network infrastructures.
Categories: Fundamentals AI Digital Sovereignty
Local AI models vs. cloud APIs. Storage, RAM requirements, quantization, offline operation, and the tool ecosystem.
Categories: Fundamentals OpenBSD
OpenBSD systems are configured through text files. hostname.if controls network interfaces, ntpd synchronizes time, doas provides delegated root privileges, and sysctl adjusts kernel parameters.
Categories: Fundamentals Init Systems
Service dependencies between services. Parallel vs. sequential startup. Detecting and resolving cyclic dependencies.
Categories: Fundamentals Package Management
Programs require libraries - nginx needs OpenSSL, PostgreSQL needs libpq. Automatic dependency graphs, conflict detection, update strategies.
Categories: Fundamentals Filesystem
Hard links vs. symbolic links (soft links). Special files in /dev as device interfaces. The inode concept and when each link type is appropriate.
Categories: Fundamentals Network SSH Security
SSH key cryptography, SSH agent, key management, and secure authentication for server access without password transmission.
Categories: Fundamentals AI
Why language models respond differently to different wording. Tokenization, system prompts, temperature, and the limits of prompt engineering.
Categories: Fundamentals Package Management
OpenBSD manages the base system and packages separately. pkg_add installs software from signed repositories, pkg_delete removes packages, and pkg_info displays package information. Updates with pkg_add -u, binary patches with syspatch. For 7.8 and 7.9.
Categories: Fundamentals Filesystems
The mount concept for USB drives, network shares, and partitions. /etc/fstab for automatic mounting during boot. tmpfs vs. persistent filesystems. Differences between ext4, btrfs, and ZFS.
Categories: Fundamentals Networking SSH Server Management
SSH configuration management, ProxyJump, bastion hosts, and efficient administration of larger server infrastructures without manual command-line parameters.
Categories: Fundamentals Security
OpenBSD implements security through privilege separation, pledge(), unveil(), W^X memory protection, and proactive code audits. Securelevels restrict root privileges, and LibreSSL replaces OpenSSL.