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

6947ch07.fm

GDPS/PPRC Management for Open Systems LUNs

GDPS/PPRC technology has been extended to manage a heterogeneous environment of z/OS and Open Systems data. If installations share their disk subsystems between the z/OS and Open Systems platforms, GDPS/PPRC, running in a z/OS system, can manage the PPRC status of devices that belong to the other platforms and are not even defined to the z/OS platform. GDPS/PPRC will also provide data consistency across both z/OS and Open Systems data.

GDPS/PPRC over Fiber Channel links

The IBM TotalStorage Enterprise Storage Server (ESS) supports PPRC over Fiber Channel for ESS Model 800. It is designed to improve throughput as compared to PPRC over ESCON links and reduces cross-site connectivity (two PPRC Fiber Channel links are considered sufficient for most workloads). The benefit of this support is the opportunity to increase the distance between sites without losing performance.

GDPS FlashCopy V2 support

Previously source and target volumes needed to reside on the same Logical Subsystem (LSS) within the disk subsystem. With FlashCopy V2 a flash copy can be created from a source in one LSS to a target in a different LSS in the same disk subsystem.

Business Continuity for Linux guests

GDPS plans to exploit the HyperSwap function in z/VM V5.1 to provide business continuity for z/OS and Linux guests. z/VM HyperSwap swaps the virtual device associated with one real disk to another and can be used to switch to a secondary disk storage subsystem mirrored by PPRC. This is a useful function for those users that share data and storage subsystems between z/OS and Linux. A SAP application server running on Linux and a SAP data base server running on a z/OS is an example of an environment that will benefit from the z/VM V5.1 HyperSwap functionality.

Much of the functionality is similar to that for z/OS systems and data. The following recovery actions are designed to support planned and unplanned outages.

￿In place re-IPL of failing operating system images.

￿Site takeover of a production site.

￿Transparent planned and unplanned HyperSwap of disk subsystem.

Near continuous availability and disaster recovery solutions require IBM Tivoli System Automation for Linux, and z/VM V5.1 in addition to other GDPS/PPRC prerequisites.

GDPS/PPRC Cross-site extended distance for Parallel Sysplex

Via a RPQ the capability to configure GDPS/PPRC or a multi-site Parallel Sysplex up to a distance of 100 kilometers (62 miles) is made possible. Support for the following has been extended for up to 100 kilometers from the previous limitation of 50 kilometers (31 miles), through use of Dense Wavelength Division Multiplexer (DWDM) equipment for:

￿External Timer Reference (ETR) links to a Sysplex Timer

￿ISC-3 links in peer mode

This support is consistent with other technologies that support the same distance, such as FICON, Peer-to-Peer Remote Copy (PPRC), and Peer-to-Peer Virtual Tape Server (PtP VTS).

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IBM 990 manual GDPS/PPRC Management for Open Systems LUNs, GDPS/PPRC over Fiber Channel links, Gdps FlashCopy V2 support
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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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