Determine the number of supported hosts per cluster in FC and FC-NVMe configurations

Contributors

The maximum number of SAN hosts that can be connected to a cluster varies greatly based upon your specific combination of multiple cluster attributes, such as the number of hosts connected to each cluster node, initiators per host, sessions per host, and nodes in the cluster.

About this task

For FC and FC-NVMe configurations, you should use the number of initiator-target nexuses (ITNs) in your system to determine whether you can add more hosts to your cluster.

An ITN represents one path from the host’s initiator to the storage system’s target. The maximum number of ITNs per node in FC and FC-NVMe configurations is 2,048. As long as you are below the maximum number of ITNs, you can continue to add hosts to your cluster.

To determine the number of ITNs used in your cluster, perform the following steps for each node in the cluster.

Steps
  1. Identify all the LIFs on a given node.

  2. Run the following command for every LIF on the node:

    fcp initiator show -fields wwpn, lif

    The number of entries displayed at the bottom of the command output represents your number of ITNs for that LIF.

  3. Record the number of ITNs displayed for each LIF.

  4. Add the number of ITNs for each LIF on every node in your cluster.

    This total represents the number of ITNs in your cluster.