Migrating a Server Without Downtime
Moving a site to a new server: syncing files with rsync, dumping and restoring databases, testing the new box before anyone points at it, and cutting DNS over safely.
Reading Linux Logs: journalctl and the Files It Did Not Replace
Finding the failure in journalctl and in traditional log files: filtering by time, unit and priority, and a repeatable method for diagnosing something that just broke.
Linux Firewalls: ufw, firewalld and What They Miss
How to configure a host firewall properly with ufw or firewalld, why Docker quietly punches holes through it, and where cloud security groups fit in.
Getting Started with Docker
A container is a process on your machine, isolated from the rest of it and shipped with everything it needs to run. Not a virtual machine — there is no…
Securing a New Linux Server
A server exposed to the internet starts receiving automated login attempts within minutes of booting. Not because anyone is interested in you — because everything with a public IP address…
Set Up a Web Server with Nginx
From a bare server to a site served over HTTPS with a certificate that renews itself. This assumes you have already worked through securing a new server — in particular…
Automated Backups with rsync and systemd Timers
By the end of this you will have nightly snapshots that each look like a complete copy while costing almost nothing in disk space, running on a schedule, logged where…
Linux Command Line Basics
The terminal looks unwelcoming because it tells you nothing about what it can do. Everything else on this site assumes you are comfortable there; this page is how you get…
sudo — Running Commands as Another User
sudo runs one command as another user, normally root, after checking that you are allowed to. The point is not convenience — it is that nobody needs to know the…
rsync — Sync Files and Directories
rsync copies files, but only the parts that changed. On the second run of a large transfer it sends almost nothing, which makes it the right tool for anything you…