Allocated storage - The space that is allocated to volumes, but not assigned.
Allocation - The entire process of obtaining a volume and unit of external storage, and setting aside space on that storage for a data set.
CIFS - Common Internet File System (CIFS) is the NAS method for Windows based systems to access the storage.
NAS - Network attached storage (NAS) utilizes the IP network instead of the storage area network (SAN) to allow access to the storage. Additionally, NAS allows the storage to be shared by multiple clients.
NFS - Network File System (NFS) is the NAS method for Unix based systems to access the storage.
SAN - Storage area network (SAN) is a managed, high-speed network that enables any-to-any interconnection of heterogeneous servers and storage systems. SAN connectivity has traditionally been the method for servers to access the centralized storage.
Shared Storage - Storage within a storage facility that is configured such that multiple homogeneous or divergent hosts can concurrently access the storage. The storage has a uniform appearance to all hosts. The host programs that access the storage must have a common model for the information on a storage device.