Design a highly available and fault-tolerant File Storage System. Your system should be able to handle large amounts of data and provide quick access for both reading and writing. Discuss the architecture, data partitioning, redundancy, and recovery mechanisms. Include considerations for user authentication and authorization.

The system should utilize microservices architecture where file upload and retrieval services are separate. Use a distributed file system such as HDFS or cloud-based storage (e.g., AWS S3) to store the files. Implement load balancers to manage requests and ensure scalability. Data can be partitioned based on user ID and file type, and replicas of the data should be stored in multiple zones for redundancy. Use IAM (Identity and Access Management) for user authentication and authorization.