Linux · Server & Cloud Setup

You terminated an instance but keep getting charged for its reserved Elastic IP. Why, and how do you stop the bill?

Answer locked. Get the free KnowCard app to reveal it — plus spaced-repetition review so it actually sticks.

This is one card from the KnowCard library — thousands more across SAP, Linux, Python and more. In the app you get the answer, AI explanations, and cards that come back right before you would forget them. Free to start on iOS, Android or the web.

More in Server & Cloud Setup

AWS calls the private network your EC2 instances live in a VPC. What isolation guarantee does that provide?

Why do most server installations deliberately run in text mode with no GUI, rather than just reusing a desktop image?

A colleague sets up a cloud instance and wants to configure RAID-1 and LVM the way they would on bare metal. What is the catch?

On real hardware or a provider root server, what disk-redundancy setup is recommended, and why does that recommendation flip on a VM or cloud instance?

You give a new internet-facing server the bare domain example.com as its hostname. Why will this decision come back to bite you?

To make a hostname reachable on the internet over both IPv4 and IPv6, which DNS records must exist?

Start learning today

Free to start — download the app or use it in your browser.