Shared logical partitions upgrade, LP1 LP2

6947ch08.fm

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

All scenarios show the hardware (physical) and the logical partition configurations before and after the upgrade. Only the 8 PUs available for CPs, IFLs, ICFs, and zAAPs are shown on

each server’s book.

Shared logical partitions upgrade

Figure 8-11 on page 210 shows a 2084-A08, software model 307 server. This one-book server configuration has seven CPs and one spare PU.

Book 0

2084-A08 Model 307

LP1

LP2

CP0	CP1	CP2	CP3	CP4	CP5	CP6	Spare

Logical	Logical	Logical	Logical	Logical	Logical	Logical	Res	Res
CP0	CP1	CP2	CP3	CP4	CP5	CP6	CP	CP
SHR	SHR	SHR	SHR	SHR	SHR	SHR
Logical	Logical
CP0	CP1
SHR	SHR

Book 0

Book 1

2084-B16 Model 309

LP1

LP2

CP0

CP1

CP2

CP3

CP4

CP5

CP6

CP7

CP8

Spare

Logical

CP0

CP1

CP2

CP3

CP4

CP5

CP6

CP7

CP8

SHR

Logical

CP0

CP1

SHR

Figure 8-11 Shared logical partitions upgrade example

There are two activated logical partitions: LP1 having seven shared (SHR) logical CPs and two reserved CPs defined, and LP2 having only two shared (SHR) logical CPs defined. Note that the number of reserved CPs for a logical partition can be higher than the number of installed PUs. This allows nondisruptive image upgrades even when new books are installed.

This example shows an upgrade to the 2084-B16, software model 309, achieved by adding concurrently one more book and LIC-CC enabling two more CPs to the physical configuration. Seven spare PUs are available for future processor upgrades. The physical upgrade ends here.

At this point, before any other configuration changes are made, the images with shared logical CPs running on this server can experience performance improvements. As there is now more available capacity (physical processors) to be used by all logical shared CPs, the “logical-to-physical processors ratio” is reducedIn. this example, before the upgrade, there were nine shared logical CPs to be dispatched into seven physical CPs. If all nine logical CPs have tasks to run, two of them have to wait. After the physical upgrade, up to nine logical CPs can run at the same time.

Now let’s see the logical upgrades. Since there is no activated partition with dedicated CP, any partition can have up to nine activated logical CPs.

210IBM eServer zSeries 990 Technical Guide

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.

IBM 990 manual Shared logical partitions upgrade, LP1 LP2

Models: 990

6947ch08.fm

Shared logical partitions upgrade

Figure 8-11 on page 210 shows a 2084-A08, software model 307 server. This one-book server configuration has seven CPs and one spare PU.

Book 0

2084-A08 Model 307

LP1

LP2

Figure 8-11 Shared logical partitions upgrade example

990 specifications