Changing node roles in a 3-node cluster (etcd + control plane → single control plane)

[tungnguyenforvia]

Hi everyone,
I’m currently running a k3s cluster at home. Here is my initial setup:

machine1: control plane, etcd, worker (init node)
machine2: control plane, etcd
machine3: control plane, etcd, worker

I want to reduce the control plane to a single node.
I started by removing machine3 from the control plane:

1. Uninstalled k3s on machine3
2. Rejoined it using the server IP of machine1
   This worked fine. My cluster now looks like:

machine1: control plane, etcd, worker (init node)
machine2: control plane, etcd
machine3: worker

My goal is to simplify the cluster to:

machine1: worker
machine2: control plane
machine3: worker

The remaining step is to convert machine1 (init node) into a worker-only node.
However, I have some concerns:

• machine1 is the initial node and currently runs etcd
• Based on Copilot feedback, removing an etcd node incorrectly could break the cluster due to quorum issues
  Unlike machine3, I’m unsure if I can safely:

1. uninstall k3s on machine1
2. then rejoin it as a worker
   Additionally:
   machine1 has NVMe storage and GPU passthrough, so I’d really prefer to keep it as a worker node.

So I'm looking for some advice here.

Thanks in advance for your help!
Have a great day!

[brandond]

AI is guessing, don't ask AI.

The init node isn't special. Delete the node from Kubernetes, and it'll get removed from etcd as well and you will be down to a single-node etcd cluster. Ensure that agent (worker) nodes all point at the remaining server, and the server does not have a server entry in its config or CLI flags.

If you have concerns, just make sure you have a recent etcd snapshot to restore from. Restoring from a snapshot always resets etcd cluster membership back to a single node anyway.