Field Note
A NAS migration is not primarily a copy operation. It is a dependency change involving identities, permissions, applications, backup jobs, network paths, media services, automations, and the people who expect those services to keep working.
The useful plan starts with data classes and consumers. It identifies what can be recreated, what is irreplaceable, what requires downtime, which paths and credentials will change, and what proof is required before the old system is retired.
The cutover should be boring: create the target, copy without deleting the source, validate counts and representative files, redirect one dependency at a time, observe, and keep a dated rollback boundary.