A LUN is a number used to identify a logical unit within a Storage Area Network (SAN). These addressable devices are typically logical disks accessed through the Small Computer System Interface (SCSI) protocol or one of its encapsulated derivatives.

A virtual volume (vVol) provides a volume-level abstraction for storage used by a virtual machine. It includes several benefits and provides an alternative to using a traditional LUN.

Persistent reservations are supported with SCSI-3 and an improvement over the earlier SCSI-2 reservations. They allow multiple client initiators to communicate with a single target while locking out other nodes. The reservations can persist even if the bus is reset for error recovery.

Microsoft WSFC is a feature of the Windows Server operating system providing fault tolerance and high availability. A set of server nodes (physical or virtual) are joined together as a cluster to provide resiliency in case of a failure. WSFC is commonly used to deploy infrastructure services include database, file, and namespaces servers.

VASA is a set of APIs providing integration of the storage arrays with vCenter for management and administration. The architecture is based on several components including the VASA Provider which handles communication between VMware vSphere and the storage systems. With ONTAP, the provider is implemented as part of ONTAP tools for VMware vSphere.

VAAI is a set of APIs that enable communication between VMware vSphere ESXi hosts and the storage devices. The API includes a set of primitive operations used by the hosts to offload storage operations to the array. VAAI can provide significant performance improvements for storage-intensive tasks.

SnapCenter is a centralized and scalable platform providing data protection for applications, databases, host file systems, and virtual machines using ONTAP storage systems. It leverages the native ONTAP technologies including Snapshot, SnapRestore, FlexClone, SnapMirror, and SnapVault.