6947ch02.fm

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

IOCP is available on z/OS, OS/390, z/VM, VM/ESA, z/VSE, and VSE/ESA operating systems, and as a standalone program on the z990 hardware console. HCD is available on z/OS, z/VM, and OS/390 operating systems.

ESCON channels (CHPID type CNC or FCV) can be managed by the Dynamic CHPID Management (DCM) function of the Intelligent Resource Director. DCM enables the system to respond to ever-changing channel requirements by moving channels from lesser-used control units to more heavily used control units, as needed.

Logically Partitioned Mode

The z990 server can only run in LPAR Mode; up to 30 logical partitions can be defined on any

z990 server. A logical partition can be defined to operate in one of the following image modes:

￿ESA/390 mode, to run:

–A z/Architecture operating system image, on dedicated or shared CPs.

–An ESA/390 operating system image, on dedicated or shared CPs.

–A Linux operating system image, on dedicated or shared CPs.

–A z/OS 1.6 or later operating system image, on any of the following:

•Dedicated or shared CPs

•Dedicated CPs and dedicated zAAPs

•Shared CPs and shared zAAPs

Note: zAAPs can be defined to any ESA/390 mode image (see Figure 2-16 on page 59). However, zAAPs are supported only by z/OS 1.6 and later operating systems. Any other operating system cannot use zAAPs, even if they are defined to the logical partition. zAAPs are not supported for a z/OS guest under z/VM.

￿ESA/390 TPF mode, to run:

–A TPF operating system image, only on dedicated or shared CPs.

￿Coupling Facility mode, to run a CF image, by loading the CFCC into this logical partition. The CF image can run any of the following definitions:

–Dedicated or shared CPs

–Dedicated or shared ICFs

–Dedicated and shared ICFs

–ICFs dedicated and CPs shared

￿Linux-only mode, to run:

–A Linux operating system image, on either:

•Dedicated or shared IFLs

•Dedicated or shared CPs

–A z/VM operating system image, on either:

•Dedicated or shared IFLs

•Dedicated or shared CPs

Table 2-4 on page 61 shows all LPAR modes, required characterized PUs and operating systems, and which PU characterizations can be configured to a logical partition image. The available combinations of dedicated (DED) and shared (SHR) processors are also shown. For all combinations, an image can also have Reserved Processors defined, allowing non-disruptive image upgrades.

60IBM eServer zSeries 990 Technical Guide

Page 73 Page 75
Page 74
Image 74
IBM 990 manual Logically Partitioned Mode
Page 73 Page 75

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.
Top Page Image Contents