6947ch08.fm

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

2084-A08 24 GB

Book 0

24 GB

32GB Max

2 Memory Cards

(16 GB each)

CUoD

+16 GB

+Model upgrade

2084-B16 40 GB

Book 0

Book 1

CUoD

+ 8 GB

24 GB

32 GB

Max

 

 

 

16 GB (Max)

 

 

2084-B16 48 GB

2 Memory Cards

(16 GB each)

2 Memory Cards (8 GB each)

Book 0

Book 1

32 GB (Max)

2 Memory Cards

(16 GB each)

 

 

2 Memory Cards

16 GB (Max)

(8 GB each)

 

 

 

Figure 8-2 CUoD for memory example

This one-book z990 model has two 16 GB memory cards, resulting in 32 GB of installed memory in total. Therefore, a concurrent memory upgrade within this model A08 can be done

up to the 32 GB limit, via LIC-CC, but a memory upgrade to 40 GB would require the book’s memory cards replacement by two 32 GB memory cards and is disruptive.

However, as shown in the example, the upgrade of this model A08 with 24 GB of memory to a model B16 with 40 GB is concurrent, as the additional book comes with 2 memory cards (in

this case, two 8 GB memory cards). The additional 16 GB memory capacity is enabled by LIC-CC on the second book (Book 1).

In the last part of this example, this model B16 server is concurrently upgraded to 48 GB, by LIC-CC enabling all the installed memory.

For a logical partition’s memory upgrade, reserved storage must have been previously defined to that logical partition. It makes use of the LPAR Dynamic Storage Reconfiguration (DSR) function. DSR allows a z/OS or OS/390 operating system running in a partition to add its reserved storage to its configuration, if any unused storage exists. When the operating system running in a partition requests an assignment of a storage increment to its configuration, PR/SM checks for any free storage and brings it online dynamically.

Concurrent memory upgrades also require that:

￿Memory must not be running in degraded mode.

Upgrades are disruptive until failing memory cards have been replaced.

192IBM eServer zSeries 990 Technical Guide

Page 205 Page 207
Page 206
Image 206
IBM 990 manual CUoD + 16 GB + Model upgrade
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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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