Mastering Proxmox - Third Edition

Loss of connectivity between Proxmox nodes

In this scenario, network connectivity is only interrupted between Proxmox nodes in a cluster. When over half of the Proxmox nodes in a cluster cannot communicate with each other, a quorum cannot be established. If multiple nodes lose network connectivity simultaneously, this usually indicates a network switch failure. This is a common scenario when a Proxmox cluster is on a dedicated management interface. So a loss of this connectivity only interrupts the quorum but not the VMs running on the nodes and users accessing it. When a quorum is lost, VMs in respective nodes function properly but from the GUI they may appear offline, including the nodes themselves, as shown in the following screenshot: ...