A company's on-premises private cloud is running on a four-node cluster with all internal storage. Each server has 12 slots for SFF disk drives, and the slots are completely full. An application…

Object storage is generally optimized for unstructured data and massive scale, but it typically does not provide the low-latency, high-IOPS block storage performance required for many performance-critical applications.

Connecting to an external SAN provides scalable, high-performance, block-level storage independently from the compute nodes, directly addressing the need for additional I/Os when internal storage cannot be expanded. SANs are designed to handle demanding application workloads and offer superior IOPS and throughput compared to internal drives alone.

ReFS (Resilient File System) is a file system feature for data integrity and resiliency, but it does not intrinsically increase the underlying physical storage's IOPS or throughput to resolve a hardware-level I/O bottleneck.

HDFS (Hadoop Distributed File System) is designed for big data processing and high-throughput sequential reads, making it unsuitable as a general-purpose, high-IOPS block storage solution for typical private cloud applications.