The IBM Eserver zSeries® 990 scalable server provides major extensions to the existing zSeries architecture and capabilities. The concept of Logical Channel Subsystems is added, and the maximum number of Processor Units and logical partitions is increased. These extensions provide the base for much larger zSeries servers. This IBM® IBM Redbooks publication is intended for IBM systems engineers, consultants, and customers who need to understand the zSeries 990 features, functions, availability, and services. IBM Eserver zSeries 990 Technical Introduction, SG24-6863 Note that the information in this book includes features and functions announced on April 7, 2004, and that certain functionality is not available until hardware Driver Level 55 is installed on the z990 server.

This IBM Redbooks publication introduces the IBM eServer zSeries 890, which represents the continuation of the scalable servers featured with the IBM eServer zSeries 990. The z890 is based on z/Architecture, the zSeries building blocks of the z990, and the virtualization technology of passed sever families. It is designed to be resilient in the unpredictable on demand world. The z890 is a single model server with a wide range of capacity settings, delivering significantly improved granularity and enriched functions over its predecessor. At the same time, the z890 is also introducing the new eServer zSeries Application Assist Processor (zAAP), which provides a Java execution environment. This publication provides information on the hardware and software features available with the z890. It also includes planning and migration considerations. This technical introduction is intended for hardware planners, system engineers, and consultants who need to understand the capabilities of the z890.