VMware’s vStorage API for Array Integration (VAAI) is one of the most-important storage technology advances of the decade, allowing the ESX to integrate and coordinate operations with supported enterprise storage arrays. IBM was notably absent from the party, but they’ve turned on the VAAI heat, releasing full support for the XIV and SVC and promising DS8000 in the near future.
The most exciting enhancements in VMware vSphere 4.1 is the addition of vStorage API for Array Integration (VAAI). This new API allows VMware ESX to offload storage processing functions to capable storage arrays, reducing the workload on the server hardware in introducing new and exciting possibilities for performance and efficiency. VAAI in ESX 4.1 includes three separate capabilities: block zeroing, full copy, and hardware assisted locking.