A storage administrator migrated an AIX host using NDM.

During a Non-Disruptive Migration (NDM), when the migration is committed, the host access to the source array is removed by deleting the masking view. The masking view is a logical grouping of host initiators, storage ports, and a storage group (which contains volumes). Deleting the masking view removes the host’s access to the volumes on the source array12. References: Dell EMC PowerMax and VMAX: Non-Disruptive Migration Best Practices and Operational Guide, VMAX/PowerMax Non-Disruptive Migration (NDM) for the IBMi host platform | Dell US Support Knowledge Base Article