How to Set Up a 3-Node Proxmox Cluster With HA

Proxmox High Availability (HA) keeps virtual machines and containers running when a node in the cluster dies. With HA enabled, the system watches the protected workloads and restarts them on another healthy node after a failure, usually within minutes.

Updated September 2026 · Mr.PlanB

Proxmox High Availability Backup Strategy

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Overview

A few prerequisites have to be in place first. You need at least three nodes to hold quorum and avoid split-brain. You need shared storage so the VMs can be reached from any node. Dependable hardware, a watchdog configuration and, if you want it, a fencing mechanism make the cluster steadier.

Creating a 3-node cluster starts in the web interface:

1. Go to Datacenter → Cluster → Create Cluster. 2. Define the cluster name and network. 3. On the other nodes, use Join Cluster and paste the join information from the first node.

Once all the nodes have joined, configure HA itself in two places:

1. Go to Datacenter → HA → Groups → Create to define an HA group. Assign nodes and priorities. You can enable “nofailback” to stop workloads migrating back to the original node once it recovers. 2. Go to Datacenter → HA → Resources → Add. Select the VM or container. Define restart and relocation limits. Assign it to the HA group.

To check that HA works, simulate a node failure. The watchdog mechanisms fire and the workload restarts on another node.

HA covers hardware failure, and it is not a backup. Replication and failover keep the service available, while a separate backup is what protects the data itself.

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