Definition
IBM Storage Virtualize is the software layer that runs IBM FlashSystem and other IBM SAN storage arrays. It is what actually performs compression, encryption, data replication, and automated tiering (Easy Tier) on the array, and it is licensed and evaluated separately from the physical array and its drives.
For an AS400/IBM i buyer, Storage Virtualize licensing becomes relevant once external FlashSystem storage is added to the environment. Which features are bundled into the base license versus sold as add-on entitlements, particularly replication and high-availability configurations, is a software licensing decision distinct from the array hardware and part number decision.