Proxmox quorum: why won't my cluster cooperate?

The quick answer

Quorum ensures the cluster has sufficient votes to make coordinated decisions and avoids conflicting changes after a network partition.

pvecm status

What's going on?

Quorum ensures the cluster has sufficient votes to make coordinated decisions and avoids conflicting changes after a network partition.

Understanding the underlying mechanism makes troubleshooting much easier than memorising a command in isolation.

Dig a little deeper

A QDevice can provide an additional arbitration vote in suitable topologies. Never treat forcibly bypassing quorum as a routine fix; investigate membership and network health.

Hands-on commands

Try these in a suitable test environment. Read each command before running it, especially if you have elevated privileges.

pvecm status
pvecm nodes
journalctl -u corosync -b