Call Home events send data that is related to the problem to the IBM product support group. This data includes the following information: 

GLYPH<SM590000> Overall system information, such as system serial number and Licensed Internal Code level 

GLYPH<SM590000> Details of the error 

GLYPH<SM590000> Error logs that can help to resolve the problem 

After the Call Home is received by the assigned IBM support group, the associated information is examined. Following analysis, an appropriate course of action is defined to resolve the problem. For example, an IBM SSR might be sent to the site location to take the corrective actions. Alternatively, the problem might be repaired or resolved remotely by IBM support personnel through a broadband (if available) or telephone (if necessary) connection. 

The TS3000 Total Storage System Console (TSSC) is the subsystem component responsible for placing the service call or Call Home when necessary. Since model 93p and release TSSC V4.7, only broadband connection is supported. 

## 2.2 Stand-alone cluster: Components, functions, and features 

In general, any cluster can be used as a stand-alone cluster. The TS7700 features several internal characteristics for High Availability (DDP RAID 6 protection, dual power supplies, and so forth). However, a grid configuration can be configured for both more high availability (HA) and Disaster Recovery (DR) functions with different levels of business continuance. For more information, see Chapter 3, “IBM TS77 00 usage considerations” on page 109. 

In this section, general information is provided about the components, functions, and features that are used in a TS7700 environment. The general concepts and information are also available in 2.2, “Stand-alone cluster: Components, functions, and features” on page 28. 

For more information about deviations and the multi-cluster grid, see 2.4, “Multi-cluster grid configurations: Components, functions, and features” on page 59. 

## 2.2.1 Views from the Host: Library IDs 

All host interaction with tape data in a TS7700 is through virtual volumes and virtual tape drives. 

You must be able to identify the logical entity that represents the virtual drives and volumes, but also address the single entity of a physical cluster. Therefore, two types of libraries are available: a composite library and a distributed library. Each type is associated with a library name and a Library ID. 

## Composite library 

The composite library  is the logical image of the stand-alone cluster or grid that is presented to the host. All logical volumes and virtual drives are associated with the composite library. In a stand-alone TS7700, the host sees a logical tape library with up to 31 3490E tape CUs. These CUs each have 16 IBM 3490E tape drives and are connected through 1 - 8 FICON channels. The composite library is defined through the Interactive Storage Management Facility (ISMF). A composite library is made up of one or more distributed libraries. 

