Enabling cluster HA and switchless-cluster in a two-node cluster

A cluster consisting of only two nodes requires special configuration settings. Cluster high availability (HA) differs from the HA provided by storage failover, and is required in a cluster if it contains only two nodes. If you have a switchless configuration, the switchless-cluster option must be enabled. Starting in ONTAP 9.2, detection of a switchless cluster is automatic.

About this task

Cluster HA ensures that the failure of one node does not disable the cluster. If your cluster contains only two nodes:
  • Enabling cluster HA requires and automatically enables storage failover and auto-giveback.
  • Cluster HA is enabled automatically when you enable storage failover.
Note: If the cluster contains or grows to more than two nodes, cluster HA is not required and is disabled automatically.

For ONTAP 9.0 and 9.1, if you have a two-node switchless configuration, the switchless-cluster network option must be enabled to ensure proper cluster communication between the nodes. In ONTAP 9.2, the switchless-cluster network option is automatically enabled. When the detect-switchless-cluster option is set to false, the switchless-cluster option will behave as it has in previous releases.

Steps

  1. Enter the following command to enable cluster HA: cluster ha modify -configured true
    If storage failover is not already enabled, you are prompted to confirm enabling of both storage failover and auto-giveback.
  2. ONTAP 9.0, 9.1: If you have a two-node switchless cluster, enter the following commands to verify that the switchless-cluster option is set:
    1. Enter the following command to change to the advanced privilege level: set -privilege advanced
      Confirm when prompted to continue into advanced mode. The advanced mode prompt appears (*>).
    2. Enter the following command: network options switchless-cluster show
      If the output shows that the value is false, you must issue the following command: network options switchless-cluster modify true
    3. Enter the following command to return to the admin privilege level: set -privilege admin