Can I create a raspberry cluster that will act in unison using it's CPUs collectively? I know that then the raspberrys would have to have the program loaded in RAM. If it is not possible then would it be more sensible to create (or modify) some low level virtual machine or abandon the project and buy a server and improve it over time?
Yes, you can create a Raspberry Pi cluster that acts in unison, using its CPUs collectively. This is commonly known as a Raspberry Pi cluster or a Raspberry Pi supercomputer. It involves connecting multiple Raspberry Pi boards together and distributing tasks across the CPUs for parallel processing. This can be useful for learning about distributed computing, cluster management, and running parallel tasks that can be divided into smaller tasks.

To build a Raspberry Pi cluster, you will need:

1. Multiple Raspberry Pi boards (preferably the same model for compatibility)
2. Networking hardware (switch, router, or Ethernet cables)
3. A microSD card for each Raspberry Pi with an OS (like Raspbian or Raspberry Pi OS) installed
4. Power supplies for each Raspberry Pi
5. A case or enclosure to hold the cluster (optional)

Once you have the hardware set up, you will need to configure the software side. There are several open-source tools and frameworks available to help you create and manage a Raspberry Pi cluster. Some popular options include:

1. MPI (Message Passing Interface): A standardized and portable message-passing system designed for parallel computing. The most common implementation for Raspberry Pi clusters is OpenMPI.
2. Kubernetes: A container orchestration platform that automates deployment, scaling, and management of containerized applications. You can use a lightweight version of Kubernetes called k3s on Raspberry Pi clusters.
3. Docker Swarm: A native clustering and scheduling tool for Docker containers, which allows you to create and manage a swarm of Docker nodes.
However, it's important to note that a Raspberry Pi cluster is not a replacement for a high-performance server or a data center. While it can be a valuable learning tool and can be used for some small-scale parallel processing tasks, its performance is limited compared to a dedicated server or cloud-based services. Depending on your specific needs and budget, you may find that investing in a server or using cloud-based resources is a more cost-effective and efficient solution for running demanding applications or services.

If your project requires a significant amount of computing power, it might be more sensible to consider buying a server or using cloud-based services and improving them over time, as needed. This would allow you to scale your resources more easily and avoid the limitations of a Raspberry Pi cluster.
What supplies do I need to assemble a Raspberry Pi cluster?
To assemble a Raspberry Pi cluster, you will need the following components:

1. Multiple Raspberry Pi boards: Choose the same model for compatibility, such as Raspberry Pi 4 Model B or Raspberry Pi 3 Model B+.
2. MicroSD cards: One for each Raspberry Pi board. These will store the operating system and any necessary software. It's recommended to use high-quality, class 10 or UHS-I (Ultra High-Speed) microSD cards for better performance.
3. Power supply: A reliable power source for each Raspberry Pi. You can use individual power adapters, or you may consider a multi-port USB power supply or a power distribution board to reduce cable clutter.
4. Networking hardware:
a. Ethernet cables: One for each Raspberry Pi board, to connect them to the network switch or router.
b. Network switch: A switch with enough ports to accommodate all your Raspberry Pi boards. It is better to choose a Gigabit switch for faster networking.
c. Router (optional): If your network doesn't already have a router, you'll need one to connect your cluster to the internet.
5. Cooling solution: Raspberry Pis may generate heat when running at full capacity, so consider adding heatsinks, fans, or a combination of both to keep the boards cool and stable.
6. Enclosure or case: A case to organize and protect the Raspberry Pi boards, power supplies, and other components. You can buy pre-made cluster cases or create your own custom design with materials like acrylic, metal, or 3D-printed plastic.
7. Operating system: Install an OS like Raspberry Pi OS (formerly Raspbian) or Ubuntu Server on each microSD card.
8. Cluster management and parallel computing software: Choose software like MPI (Message Passing Interface), Kubernetes, or Docker Swarm to manage your cluster and distribute tasks across the nodes.
9. Optional accessories: Additional items like an HDMI cable, keyboard, mouse, and monitor might be needed for the initial setup and troubleshooting of your Raspberry Pi boards.

Once you've gathered all the necessary components, you can assemble your Raspberry Pi cluster by connecting the hardware, installing the operating system on each board, and configuring the cluster management and parallel computing software to distribute tasks across the nodes.
I want to provision 32 Raspberry Pis at once. How do I do that without manually installing the OS to each one and needing to connect each Pi to a monitor?
To achieve the objective of provisioning 32 Raspberry Pis simultaneously without manually installing the OS to each one and connecting each Pi to a monitor, the following steps can be taken:

Set up a centralized installation server that can deliver the OS to each Raspberry Pi at once. This can be done by installing and configuring a network boot server such as PXE (Preboot Execution Environment) server on a machine on the same network as the Pis.

Connect all the Pis to the network and make sure they are configured to boot from the network server.

Prepare a customized OS image with all the settings and software needed for each Raspberry Pi. This can be done by installing and configuring the OS on one Raspberry Pi and then creating an image of the SD card.

Use the image to provision all the Pis simultaneously by booting them from the network server and selecting the OS image to install.

By following these steps, you can provision 32 Raspberry Pis at once without the need for manual installation and monitor connection.