Settings that Influence VM Node Selection

Explains VM options that control which node a VM runs on, including HA group affinity and anti-affinity, preferred node, preferred cluster, and failover cluster settings.

Each time a VM is powered on or migrated, the system decides where to run the VM based on user-specified VM options as well as balancing workloads across available nodes.

VM options used in deciding node selection for running a VM:

• HA Group

  • Node Affinity: (value starts with a "+", e.g. "+commapp") The system attempts to run VMs with the same HA Group value on the same node. This is used to coalesce application-related workloads to a single physical node for performance optimization.
  • Node Anti-affinity: (value does NOT start with "+", e.g. "webservers") VMs with the same HA Group value are run on separate nodes to provide high availability of applications or services.
• Preferred Node: a specific node is selected as the first-choice
• Preferred Cluster: nodes in specified cluster used as first choice
• Failover Cluster: nodes in specified cluster used as next choice when preferred cluster is not available

For more information about these and other VM options, see: Product Guide - Virtual Machine Fields