Raspberry Pi Cluster, Part 1 - Hardware

Introduction

Ever since I first saw a Raspberry Pi back in 2012, I’ve been a little bit obsessed with them. I don’t know if it was simply because of it’s size, it’s super low price or the endless possibilities that it gives an enquiring mind, but I remember how my mind was blown by this credit card size computer that cost around £20 (if my memory serves me correct).

My original Raspberry Pi 1B

My original Raspberry Pi 1B

Fast forward a few years. I started to read more and more about clustering Raspberry Pi’s and how people have built some amazing projects on their clusters, so I decided that I definitely, 100% needed one in my life. In this series of blog posts, I’m going to detail the journey and the approach that I took to get the cluster online.

If this project goes anything like most of my previous projects, it will most likely be totally over-the-top and unnecessarily complicated. But that’s fine with me, it’s all about the learning and fixing issues as I find them.

This post is a bit meta - it has been written before I have completed the project. The plan is to host this site on the cluster itself, so if you are reading this, it means I must have worked it all out and got the site live.

Well done future me!

What this series is and isn’t

The series is intended to document what I did to get this cluster up and running, it’s not designed to be a step-by-step tutorial. There are plenty of other tutorials like this out there on the Internet, so have a look around and you’ll find a few such tutorials.

However, it’s worth saying that it is a still a pretty niche subject and the tutorials do vary in quality. Also, bear in mind that the hardware and software is updated regularly, so what worked a year ago may not (actually, that is more like probably won’t) work today. It should give you a good start through.

The hardware list

SPOILER: This isn't the final setup. If you are following along, read the entire series first as there are many issues that I had to resolve before I got it all working.

The main choice I had to make at the beginning was which flavour of Raspberry Pi I was going to use. At the time of writing, the Pi 4 has been around for a few years and is pretty much the recommended base for a Pi Cluster (Alex Ellis recommends giving away the Pi 3b+’s as they are not viable anymore), but a few of the tutorials out there do use the older Pi 3b+ boards.

One of the main objectives of the project was to keep the costs down as much as possible. As I already owned a couple of Pi 3b+ boards, I decided to simply purchase a couple more of these to build a 4 node Pi 3b+ cluster.

So here was my initial shopping list:

All in, I spent around £110 on the extra bits, on top of the parts I already owned.

The individual hardware components

The individual hardware components

Now I have all the components, it’s time to stick them all together to build myself an awesome little super computer.

Next, Part 2 - Assembling the cluster