Support for persistent ports

Beginning in ONTAP 9.8, persistent ports are enabled by default on All SAN Arrays (ASAs) that are configured to use the FC protocol. Persistent ports are only available for FC and require zone membership identified by World Wide Port Name (WWPN).

Persistent ports reduce the impact of takeovers by creating a shadow LIF on the corresponding physical port of the HA partner. When a node is taken over, the shadow LIF on the partner node assumes the identity of the original LIF, including the WWPNe. Before the status of path to the taken over node is changed to faulty, the shadow LIF appears as an Active/Optimized path to the host MPIO stack, and I/O is shifted. This reduces I/O disruption because the host always sees the same number of paths to the target, even during storage failover operations.

For persistent ports, the following FCP port characteristics should be identical within the HA pair:

If any of these characteristics are not identical within the HA pair, the following EMS message is generated:

EMS : scsiblade.lif.persistent.ports.fcp.init.error

For more information on persistent ports, see Best Practices for Scalable SAN.

NetApp Technical Report 4080: Best Practices for Scalable SAN ONTAP 9