Ubuntu makes it very easy to set up full disk encryption, but it requires you to wipe the entire disk if you want the wizard to do it for you, so this is how you can set it up manually.

This page is a collection of useful commands or one-liners collected through the years. They are sorted in general categories, but I’ve attempted to describe them as well as I can so hopefully CTRL+F will work decently if you know what you’re looking for.

fail2ban is commonly used to take a certain action, such as automatically blocking an IP, after repeated authentication failures or other generally bad behavior against applications, as detected by regex matching against log output.