Here, we will guide you through the process of creating the installation image for your cluster's master node. First, you need to download the cluster operating system you want to use and copy it to a bootable microSD card. Afterwards, you can boot up your master node with the microSD card and either copy the OS to its internal memory or continue using the microSD card for operation. This book will use the second approach and use a 16 GB microSD card for additional swap space. Let's first start with a short introduction to bootable SD cards.
There are some vendors who announce that their cards are bootable and others might not be. This is simply not true. Every microSD card and every memory stick is bootable. The only thing that has to be done is to create the correct partition table in the master boot record.
To give an example, let's assume that your SD card is inserted into your computer running your Linux...