## 2.1 TS7700 architecture 

The architectural design of the IBM TS7700 and many of its capabilities are described in this section. A short description of the original IBM Virtual Tape Server (VTS) architecture is included to help you understand the differences. 

The TS7700 family now includes the following different models: 

GLYPH<SM590000> IBM TS7770, including the IBM TS7770D, IBM TS7770T, and IBM TS7770C 

GLYPH<SM590000> IBM TS7760, including the IBM TS7760D, IBM TS7760T, and IBM TS7760C 

Although some differences exist between these models, the underlying architecture is the same. Any function or feature that is unique or behaves differently for a specific model is clearly stated. If this distinction is not made, assume that it is common across all models. 

Note:  Consider the following points: 

GLYPH<SM590000> When the TS7700 is referenced, it implies all models and types, including the TS7770, TS7760 and all D, T and C submittals. 

GLYPH<SM590000> When the function is applicable to models that are disk-only, TS7700D is used. 

GLYPH<SM590000> If the functions are applicable to all tape attached models only, TS7700T is used. 

GLYPH<SM590000> If the functions are applicable to all cloud storage tier-supported TS7700s, TS7700C is used. 

GLYPH<SM590000> If the function is applicable to only a specific version of the TS7700, such as the TS7770, TS7770D, TS7770T, TS7770C, TS7760, TS7760D, TS7760T, or TS7760C, the product name or names are referenced. 

## 2.1.1 Monolithic design of an exiting IBM Virtual Tape Server 

IBM virtual tape existed since 1997. The first three generations of the IBM 3494 VTS (B16, B18, and B10/20) performed all functions within a single IBM System p server, including handling all RAID function. 

Peer-to-peer (PTP) functions were created for the B18 and B10/20 models by using more hardware components. The complex design reached an architectural limit that made it difficult to add enhancements, especially around three or more site-based business continuances. A fundamental architecture change was required. 

IBM decided that it was time to create a next-generation solution with a focus on scalability and business continuance. Many components of the original VTS were retained, although others were redesigned. 

## 2.1.2 Modular design of the TS7700 

The result was the TS7700 Virtualization Engine, which was released in 2006. 

The modular design of the TS7700 separates the functions of the system into smaller components. These components feature well-defined functions that are connected by open interfaces. The platform enables components to be scaled up from a small configuration to a large one. This feature provides the capability to grow the solution to meet your business objectives. 

