You must replace a when the existing HBA fails. Keep these guidelines in mind when you replace an HBA host port:
Depending on how the host is taken offline, reservation data and registration data for the HBA host port that are no longer included in the configuration might be kept
along with current reservation and registration data. Accumulation of old persistent reservation data eventually might cause
the to reach the upper boundary of permitted initiator ports. The controller also might send an Insufficient Registration Resources error if another HBA host port tries to register. The maximum number of persistent reservations per logical drive depends
on your system configuration. The maximum number of registrants per logical drive is 512.
To prevent an Insufficient Registration Resources error, you must remove the logical drive reservations and registrations of the HBA host ports that are no longer included
in the configuration. Remove logical drive reservations only during scheduled maintenance downtimes to prevent interference
with cluster server operations.