My Proxmox server is running out of room, so I bring three Proxmox VE nodes together into one cluster and migrate Pi-hole to another host.
This walkthrough starts with Home Assistant, Pi-hole and Zigbee2MQTT on the existing node, plus two empty Proxmox nodes. I cover preparation, hosts files, time synchronisation, cluster creation, joining nodes, quorum checks and migration troubleshooting.
This is a basic cluster with manual migration. High availability and automatic failover are not configured.
Follow along
The companion guide covers the commands, expected results and troubleshooting steps, including a checklist you can repeat on each node.
Technical clarifications
Clustering does not pool the nodes’ RAM. Two-node clusters are possible; a QDevice provides an additional vote rather than hosting VMs. Accurate time synchronisation is required. HA is a separate configuration and can use suitable shared storage or supported replication.
In this video
- 00:00 My Proxmox server is running out of room
- 01:22 What is a Proxmox cluster?
- 02:23 One existing node and two empty nodes
- 02:51 Updates and why I want a cluster
- 04:16 Checks before creating the cluster
- 05:46 Running the preparation commands
- 06:07 Gather each server’s details
- 06:47 Edit the hosts files
- 07:56 Check time synchronisation
- 08:11 Repeat preparation on the other nodes
- 10:12 Run the final checks on all three nodes
- 11:41 Create the cluster on PVE1
- 12:37 Join PVE2 to the cluster
- 14:43 Add PVE3
- 14:59 Verify cluster membership and quorum
- 16:08 Prepare a VM for migration
- 17:00 Migration fails with an SSH error
- 17:39 Investigate the SSH problem
- 19:43 Migrate Pi-hole to another node
- 21:40 Wrap-up and future Proxmox plans

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