The TS7740 Virtualization Engine, displayed by the host as a 3957-V0x, utilizes virtual and physical tape drives, disk cache, and integrated hierarchical storage management to provide a data storage solution. The TS7740 Virtualization Engine expands upon the capabilities provided by the 3494 VTS and the Peer-to-Peer VTS. The TS7740 Virtualization Engine (each known as a cluster) can be interconnected to form a grid configuration. Using advanced policy management, also referred to as outboard policy management, you can create policies to perform tasks such as creating a secondary copy of data, creating one or more copies across a grid network, and controlling physical volume pooling. This solution provides high availability, disaster recovery, and disaster recovery testing capabilities.

A grid configuration presents itself to the attached hosts as a single library image with 3490-E emulated virtual tape devices. The copying of the volumes in a grid configuration is handled by the clusters and is completely transparent to the host. Each TS7740 Virtualization Engine in a grid manages its own set of physical volumes and maintains the relationship between logical volumes and the physical volumes on which they reside.

The TS7740 Virtualization Engine is supported by the host similarly to the Peer-to-Peer VTS. The TS7740 Virtualization Engine appears as one library image to the attached hosts. The single library image is referred to as the composite library, the logical image of the grid. The underlying clusters of the composite library are referred to as the distributed libraries. As with the Peer-to-Peer VTS, all drives and volumes are associated with the composite library with the distributed libraries being used to report on the state of each library. A stand-alone TS7740 Virtualization Engine (single cluster grid) is a grid consisting of one cluster. Even though the single cluster grid consists of one VTS (distributed library), this is different from the standalone VTS, and requires that a composite library and a distributed library be defined at the host in order to represent the TS7740 Virtualization Engine. Multiple TS7740 Virtualization Engines (multi-cluster grid) form a grid consisting of multiple clusters, and to the host, consists of one composite library and multiple distributed libraries. All the libraries (composite and distributed) must be defined to the host.