VMware vSphere Storage APIs – Array Integration (VAAI)
Dec 12, 2012
"In a virtualized environment, storage operations traditionally have been expensive from a resource perspective. Functions such as cloning and snapshots can be performed more efficiently by the storage device than by the host.
VMware vSphere Storage APIs – Array Integration (VAAI), also referred to as hardware acceleration or hardware offload APIs, are a set of APIs to enable communication between VMware vSphere ESXi hosts and storage devices. The APIs define a set of “storage primitives” that enable the ESXi host to offload certain storage
operations to the array, which reduces resource overhead on the ESXi hosts and can significantly improve performance for storage-intensive operations such as storage cloning, zeroing, and so on. The goal of VAAI is to help storage vendors provide hardware assistance to speed up VMware I/O operations that are more efficiently accomplished in the storage hardware."