Raspberry Pi 4 as a Proxmox cluster node

So I finally took the plunge.

After installing Proxmox on a Raspberry Pi 4, I finally joined it to my homelab cluster today.

Before that, I did a few checks.

I made sure I allowed root login via SSH. This is done by editing /etc/ssh/sshd_config and making sure that the following line is present:

PermitRootLogin yes

Then, I made sure I could log in to the RPi4 as root via ssh. I made sure I could, from the RPi4, log in to the other nodes via ssh. And then I made sure I could log in from the main node (Poweredge R720) to the RPi4.

Why? Because if the nodes have issues communicating with each other, this could mean that quorum cannot be reached, and that will end up with all kinds of issues on the cluster. Trust me, I know... from a previous experience of trying to set up a RPi4 as a Qdevice, which resulted in five hours of fixing.

So now, I can safely power down my Poweredge R430 when it is not in use. My main use for it is as a machine for rendering videos, which is not something that I do often. In a two-node cluster, it will have to remain up even though I have no use for it; otherwise, quorum cannot be reached and the main node (R720) cannot start or stop any VMs. In a three-node cluster, as long as the R720 and RPi4 are running, quorum is reached and VMs can be started or stopped. And a RPi4 definitely consumes less electricity than a R430 rack server.

Next is to get a UPS for the RPi4...