Draft Document for Review April 7, 2004 6:15 pm

6947ch01.fm

For those CF structures that support use of System-Managed CF Structure Duplexing, customers have the ability to dynamically enable or disable, selectively by structure, the use of System-Managed CF Structure Duplexing.

Customers interested in deploying System-Managed CF Structure Duplexing in their test, development, or production Parallel Sysplex will need to read the technical paper System-Managed CF Structure Duplexing, GM13-0103 and analyze their Parallel Sysplex environment to understand the performance and other considerations of using this function.

GM13-0103 is available at these Web sites:

http://www.ibm.com/server/eserver/zSeries/pso

http://www.ibm.com/servers/eserver/zSeries/library/techpapers/gm130103.html

1.3.10 Intelligent Resource Director (IRD)

Exclusive to IBM's z/Architecture is IntelligenResource Director (IRD), a function that optimizes processor and channel resource utilization across logical partitions based on workload priorities. IRD combines the strengths of the PR/SM, Parallel Sysplex clustering, and z/OS Workload Manager.

Intelligent Resource Director uses the concept of an “LPAR cluster”, the subset of z/OS systems in a Parallel Sysplex cluster that are running as logical partitions on the same z900 server. In a Parallel Sysplex environment, Workload Manager directs work to the appropriate resources, based on business policy. With IRD, resources are directed to the priority work. Together, Parallel Sysplex technology and IRD provide flexibility and responsiveness to e-business workloads that are unrivaled in the industry.

IRD has three major functions: LPAR CPU Management, Dynamic Channel Path Management, and Channel Subsystem Priority Queuing, which are explained in the following sections.

Channel Subsystem Priority Queuing

Channel Subsystem Priority Queuing on the z900 allows priority queueing of I/O requests within the Channel Subsystem, and the specification of relative priority among logical partitions. WLM in goal mode sets priorities for a logical partition, and coordinates this activity among clustered logical partitions.

Dynamic Channel Path Management

This feature enables customers to have channel paths that dynamically and automatically move to those ESCON I/O devices that have a need for additional bandwidth due to high I/O activity. The benefits are enhanced by the use of goal mode and clustered logical partitions.

LPAR CPU Management

Workload Manager (WLM) dynamically adjusts the number of logical processors within a logical partition and the processor weight, based on the WLM policy. The ability to move the CPU weights across an LPAR cluster provides processing power to where it is most needed, based on WLM goal mode policy.

1.3.11 Hardware consoles

Hardware Management Console and Support Element interface

On z990 servers, the Hardware Management Console (HMC) provides the platform and user interface that can control and monitor the status of the system via the two redundant Support Elements installed in each z990.

Chapter 1. IBM zSeries 990 overview 15

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IBM 990 manual Intelligent Resource Director IRD, Hardware consoles
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990 specifications

The IBM 990 series, often referred to in the context of IBM's pioneering efforts in the realm of mainframe computing, represents a unique chapter in the history of information technology. Introduced in the late 1960s, the IBM 990 series was designed as a powerful tool for enterprise-level data processing and scientific calculations, showcasing the company's commitment to advancing computing capabilities.

One of the main features of the IBM 990 was its architecture, which was built to support a wide range of applications, from business processing to complex scientific computations. The system employed a 32-bit word length, which was advanced for its time, allowing for more flexible and efficient data handling. CPUs in the IBM 990 series supported multiple instructions per cycle, which contributed significantly to the overall efficiency and processing power of the machines.

The technology behind the IBM 990 was also notable for its use of solid-state technology. This provided a shift away from vacuum tube systems that were prevalent in earlier computing systems, enhancing the reliability and longevity of the hardware. The IBM 990 series utilized core memory, which was faster and more reliable than the magnetic drum memory systems that had been standard up to that point.

Another defining characteristic of the IBM 990 was its extensibility. Organizations could configure the machine to suit their specific needs by adding memory, storage, and peripheral devices as required. This modular approach facilitated the growth of systems alongside the technological and operational demands of the business environments they served.

In terms of software, the IBM 990 series was compatible with a variety of operating systems and programming environments, including FORTRAN and COBOL, enabling users to access a broader array of applications. This versatility was a significant advantage, making the IBM 990 an appealing choice for educational institutions, research facilities, and enterprises alike.

Moreover, the IBM 990 was engineered to support multiprocessing, which allowed multiple processes to run simultaneously, further increasing its effectiveness in tackling complex computing tasks.

In summary, the IBM 990 series represents a significant advancement in computing technology during the late 20th century. With a robust architecture, versatile configuration options, and a focus on solid-state technology, the IBM 990 facilitated substantial improvements in data processing capabilities, making it a cornerstone for many businesses and academic institutions of its time. Its impact can still be seen today in the continued evolution of mainframe computing.
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