NinjaStars is a specialized tool commonly used to determine current compaction ratios on Primera arrays. While other tools might provide a range of data management functionalities, NinjaStars is specifically geared towards detailed analysis and metrics related to storage efficiency, including compaction ratios.

To create a full copy replica of a database for performance testing, the appropriate technology to use is a 'clone.' A clone is an exact, full copy of the database which operates independently from the original, ensuring that performance testing does not affect the production database. Other technologies like deduplication, snapshots, or synthetic fulls do not produce a standalone, full copy suitable for the intended use.

The best recommendation for the customer would be HPE Nimble dHCI. This solution is designed to simplify IT management and reduce the burden on limited IT staff. It offers automated management and simplified operations, which aligns with the customer's need for easier management. Additionally, HPE Nimble dHCI does not rely on fibre channel, which addresses the customer's desire to move away from this technology. Options like HPE Primera and HPE XP8 are high-end and might be overbudget, whereas HPE StoreOnce is focused on data backup rather than replacing primary storage.

To meet additional I/O requirements, upgrading from HF40 to HF60 is logical, as HF60 typically indicates a higher performance and capacity compared to HF40 controllers. Therefore, HF60 would be the appropriate upgrade to support additional I/O needs.