Systems Notes
A small collection of operational notes, command references and troubleshooting reminders for Linux, Windows and network infrastructure. Mostly things that are useful once every six months and impossible to remember when they are actually needed.
Linux / systemd
Service status, logs, sockets, permissions and common Ubuntu maintenance commands.
DNS & TLS
dig, DNS propagation, ACME certificates,
Caddy configuration and certificate diagnostics.
Windows
PowerShell snippets, network diagnostics, services and useful administration commands.
Tools
References to frequently used administration and troubleshooting utilities.
Recent notes
16 Aug 2026
Caddy on Ubuntu 24.04
Service layout, systemd permissions and automatic
certificate handling.
12 Aug 2026
DNS propagation checks
Querying authoritative servers directly and comparing
answers with public recursive resolvers.
03 Aug 2026
Useful socket diagnostics
Quick checks with
ss, curl,
dig and PowerShell.
27 Jul 2026
Ubuntu server baseline
A short post-install checklist for small virtual machines.