Virtualization is a disruptive technology in every sense of the word. By abstracting and simplifying physical resources, virtualization enables dynamic utilization. But this “translation†from physical to virtual disrupts the assumptions that enable performance and flexibility of physical devices such as storage arrays.
block zeroing
VMware VAAI Storage Array Support in Plain English
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.