TS7700 Cluster A TS7700 cluster is a physical hardware component that provides the FICON host connections and 256 virtual tape device addresses. In the TS7740 configuration, the cluster includes both the disk cache and an attached IBM tape library. In a TS7720 configuration, the emulated tape volumes exist only in disk-based cache. A TS7720 Cluster does not attach to a physical tape library.
TS7720 Cluster The TS7720 Cluster provides a disk-only TS7700 Virtualization Engine virtual tape subsystem.
TS7740 Cluster The TS7740 Cluster combines the TS7700 Virtualization Engine with a tape library to form a virtual tape subsystem.
TS7700 Grid A TS7700 Grid refers to two or more physically separate TS7700 Clusters connected to one another by a TCP/IP network. A TS7700 Grid can contain disk-only clusters that do not attach to a physical tape library, clusters that do attach to a physical tape library, or a combination of both.
The TCP/IP infrastructure connecting a TS7700 Grid is known as the Grid Network. The grid configuration is used to provide disaster recovery through remote virtual volume replication among multiple clusters that are geographically separated. A high-availability configuration can be achieved with multiple clusters located in close proximity.
The TS7700 clusters maintain an internal database containing information about the device and the associated grid. The IBM Bulk Volume Information Retrieval (BVIR) interface allows users to extract information about logical volumes, physical volumes, real-time and historical statistics, cache and performance data, and replication status for a cluster or grid.
The BVIR function was first introduced with early-generation IBM Virtual Tape Servers and has expanded over many years. A wealth of information can be extracted from the TS7700s. The BVIR interface uses a standard labeled tape volume both to initiate a request for information and to return the results. By using a standard tape volume, no special interfaces or access methods are required for an application to use this facility. The data returned from a BVIR request can be character or binary data, depending on the type of request, and typically requires post-processing for customer analysis. While IBM provides tape tools to convert and analyze BVIR data, the process is cumbersome. After extracting BVIR data, records must be converted using a mainframe-based utility program and then transferred to a PC for processing with Microsoft Excel and PowerPoint. The tools do not consolidate data from different Clusters or Grids, nor do they interface with external tape data from OAM or a customer's tape management system. Finally, these tape tools are not officially maintained by IBM; the original author has retired.