Init System (5)

• Understanding Systemd Units and Unit Files (digitalocean.com) tutorial
  What systemd units are and how unit file sections and directives fit together
  Service Management Systemd #
• journalctl(1) - Linux manual page (man7.org) reference
  querying and filtering the systemd journal: field matches, boot ranges, output formats
  Command Line Logging #
• systemd.network(5) - Linux manual page (man7.org) reference
  systemd-networkd .network unit settings: interface matching, addressing, DHCP client and server
  DHCP Network Routing #
• System and Service Manager (systemd.io) tool
  Upstream home of PID 1: service manager plus journald, networkd, resolved and the unit ecosystem
  Logging #
• systemd - ArchWiki (wiki.archlinux.org) reference
  Unit files, targets, journalctl and service control as practised on Arch
  Arch Linux #