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Intelligent Resource Director
On IBM mainframes running the z/OS operating system, Intelligent Resource Director (IRD) is software that automates the management of CPU resources and certain I/O resources. IRD is implemented as a collaboration between Workload Manager (WLM), a component of z/OS, and the PR/SM Logical Partitioning (LPAR) hypervisor, a function of the mainframe hardware. Major IRD functions are: *Logical CP Management - where IRD dynamically varies logical processors on- and off-line. (This does not apply to zIIPs or zAAPs.) *Weight Management - where IRD dynamically redistributes LPAR weights between members of an LPAR Cluster. (An LPAR Cluster is the set of members of a Parallel Sysplex on a single mainframe footprint.{{Clarify, date=February 2009) The total of the weights for the LPAR Cluster remains constant as weights are shifted between the members. (Linux on IBM Z LPARs can also participate in Weight Management.) * CHPID Management - where logical channel paths are moved between members o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM Mainframe
IBM mainframes are large computer systems produced by IBM since 1952. During the 1960s and 1970s, IBM dominated the large computer market. Current mainframe computers in IBM's line of business computers are developments of the basic design of the IBM System/360. First and second generation From 1952 into the late 1960s, IBM manufactured and marketed several large computer models, known as the IBM 700/7000 series. The first-generation 700s were based on vacuum tubes, while the later, second-generation 7000s used transistors. These machines established IBM's dominance in electronic data processing ("EDP"). IBM had two model categories: one (701, 704, 709, 7030, 7090, 7094, 7040, 7044) for engineering and scientific use, and one (702, 705, 705-II, 705-III, 7080, 7070, 7072, 7074, 7010) for commercial or data processing use. The two categories, scientific and commercial, generally used common peripherals but had completely different instruction sets, and there were incompatibiliti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Z/OS
z/OS is a 64-bit operating system for IBM z/Architecture mainframes, introduced by IBM in October 2000. It derives from and is the successor to OS/390, which in turn was preceded by a string of MVS versions.Starting with the earliest: * OS/VS2 Release 2 through Release 3.8 * MVS/System Extensions (MVS/SE) * MVS/System Product (MVS/SP) Version 1 * MVS/System Product Version 2 (MVS/Extended Architecture, MVS/XA) * MVS/System Product Version 3 (MVS/Enterprise Systems Architecture, MVS/ESA) * MVS/ESA SP Version 4 * MVS/ESA SP Version 5 Like OS/390, z/OS combines a number of formerly separate, related products, some of which are still optional. z/OS has the attributes of modern operating systems, but also retains much of the older functionality originated in the 1960s and still in regular use—z/OS is designed for backward compatibility. Major characteristics z/OS supportsSome, e.g., TSO/E, are bundled with z/OS, others, e.g.,CICS, are separately priced. stable mainframe fac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer from cellular phones and video game consoles to web servers and supercomputers. The dominant general-purpose personal computer operating system is Microsoft Windows with a market share of around 74.99%. macOS by Apple Inc. is in second place (14.84%), and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Workload Manager
In IBM mainframes, Workload Manager (WLM) is a base component of MVS/ESA mainframe operating system, and its successors up to and including z/OS. It controls the access to system resources for the work executing on z/OS based on administrator-defined goals. Workload Manager components also exist for other operating systems. For example, an IBM Workload Manager is also a software product for AIX operating system. Workload Manager On a mainframe computer many different applications execute at the same time. The expectations for executing work are consistent execution times and predictable access to databases. On z/OS the Workload Manager (WLM) component fulfills these needs by controlling work's access to system resources based on external specifications by the system administrator. The system administrator classifies work to service classes. The classification mechanism uses work attributes like transaction names, user identifications or program names which specific applications ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PR/SM
A logical partition (LPAR) is a subset of a computer's hardware resources, virtualized as a separate computer. In effect, a physical machine can be partitioned into multiple logical partitions, each hosting a separate instance of an operating system. PR/SM Although the terms ''PR/SM'' and ''LPAR'' are often used interchangeably in IBM Z, including in IBM documentation, ''PR/SM'' was not present in the IBM 370/168's Virtual Machine Facility/370; it came in with the IBM 3090, years later. Formally, LPAR designates the mode of operation or an individual logical partition, whereas PR/SM is the commercial designation of the feature. In mainframe computing PR/SM (Processor Resource/System Manager) is a type-1 Hypervisor (a virtual machine monitor) that allows multiple logical partitions to share physical resources such as CPUs, I/O channels and LAN interfaces; when sharing channels, the LPARs can share I/O devices such as direct access storage devices (DASD). PR/SM is integrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LPAR
A logical partition (LPAR) is a subset of a computer's hardware resources, virtualized as a separate computer. In effect, a physical machine can be partitioned into multiple logical partitions, each hosting a separate instance of an operating system. PR/SM Although the terms ''PR/SM'' and ''LPAR'' are often used interchangeably in IBM Z, including in IBM documentation, ''PR/SM'' was not present in the IBM 370/168's Virtual Machine Facility/370; it came in with the IBM 3090, years later. Formally, LPAR designates the mode of operation or an individual logical partition, whereas PR/SM is the commercial designation of the feature. In mainframe computing PR/SM (Processor Resource/System Manager) is a type-1 Hypervisor (a virtual machine monitor) that allows multiple logical partitions to share physical resources such as CPUs, I/O channels and LAN interfaces; when sharing channels, the LPARs can share I/O devices such as direct access storage devices (DASD). PR/SM is integrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypervisor
A hypervisor (also known as a virtual machine monitor, VMM, or virtualizer) is a type of computer software, firmware or hardware that creates and runs virtual machines. A computer on which a hypervisor runs one or more virtual machines is called a ''host machine'', and each virtual machine is called a ''guest machine''. The hypervisor presents the guest operating systems with a virtual operating platform and manages the execution of the guest operating systems. Unlike an emulator, the guest executes most instructions on the native hardware. Multiple instances of a variety of operating systems may share the virtualized hardware resources: for example, Linux, Windows, and macOS instances can all run on a single physical x86 machine. This contrasts with operating-system–level virtualization, where all instances (usually called ''containers'') must share a single kernel, though the guest operating systems can differ in user space, such as different Linux distributions with the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mainframe Computer
A mainframe computer, informally called a mainframe or big iron, is a computer used primarily by large organizations for critical applications like bulk data processing for tasks such as censuses, industry and consumer statistics, enterprise resource planning, and large-scale transaction processing. A mainframe computer is large but not as large as a supercomputer and has more processing power than some other classes of computers, such as minicomputers, servers, workstations, and personal computers. Most large-scale computer-system architectures were established in the 1960s, but they continue to evolve. Mainframe computers are often used as servers. The term ''mainframe'' was derived from the large cabinet, called a ''main frame'', that housed the central processing unit and main memory of early computers. Later, the term ''mainframe'' was used to distinguish high-end commercial computers from less powerful machines. Design Modern mainframe design is characterized less b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ZIIP
In IBM System z9 and successor mainframes, the System z Integrated Information Processor (zIIP) is a special purpose processor. It was initially introduced to relieve the general mainframe central processors (CPs) of specific Db2 processing loads, but currently is used to offload other z/OS workloads as described below. The idea originated with previous special purpose processors, the zAAP, which offloads Java processing, and the IFL, which runs Linux and z/VM but not other IBM operating systems such as z/OS, DOS/VSE and TPF. A System z PU (processor unit) is "characterized" as one of these processor types, or as a CP (Central Processor), or SAP (System Assist Processor). These processors do not contain microcode or hardware features that accelerate their designated workloads. Instead, by relieving the general CP of particular workloads, they often lead to a higher workload throughput at reduced license fees. DB2 for z/OS V8 was the first application to exploit the zIIP, but no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ZAAP
The IBM System z Application Assist Processor (zAAP), previously known as the zSeries Application Assist Processor, is a mainframe processor introduced by IBM in 2004. zAAP engines are dedicated to running specific Java and XML workloads under z/OS, accelerating performance. zAAPs are available for zSeries 990 and 890 servers and later zSeries and zEnterprise models. Beginning with the IBM z13, the zAAP functionality is integrated with zIIP processors (zAAP on zIIP). Currently a zAAP engine contains the same underlying hardware as any other mainframe engine. However, IBM uses microcode to limit code execution to Java and XML workloads only. As with Integrated Facility for Linux (IFL) and zIIP, zAAPs are not specifically optimized to run Java faster or better. IBM does not change the "software model" or MSU rating on its mainframes with the installation of zAAPs. Consequently, IBM's customers do not incur software license charges for their zAAPs, reducing their costs of running ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM Parallel Sysplex
In computing, a Parallel Sysplex is a cluster of IBM mainframes acting together as a single system image with z/OS. Used for disaster recovery, Parallel Sysplex combines data sharing and parallel computing to allow a cluster of up to 32 systems to share a workload for high performance and high availability. Sysplex In 1990, IBM mainframe computers introduced the concept of a Systems Complex, commonly called a Sysplex, with MVS/ESA SPV4.1. This allows authorized components in up to eight logical partitions (LPARs) to communicate and cooperate with each other using the XCF protocol. Components of a Sysplex include: * A common time source to synchronize all member systems' clocks. This can involve either a Sysplex timer (Model 9037), or the Server Time Protocol (STP) * Global Resource Serialization (GRS), which allows multiple systems to access the same resources concurrently, serializing where necessary to ensure exclusive access * Cross System Coupling Facility ( XCF), which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux On IBM Z
Linux on IBM Z or Linux on zSystems is the collective term for the Linux operating system compiled to run on IBM mainframes, especially IBM Z / IBM zSystems and IBM LinuxONE servers. Similar terms which imply the same meaning are ''Linux/390'', ''Linux/390x,'' etc. The three Linux distributions certified for usage on the IBM Z hardware platform are Red Hat Enterprise Linux, SUSE Linux Enterprise Server, and Ubuntu. History Linux on IBM Z originated as two separate efforts to port Linux to IBM's System/390 servers. The first effort, the "Bigfoot" project, developed by Linas Vepstas in late 1998 through early 1999, was an independent distribution and has since been abandoned. IBM published a collection of patches and additions to the Linux 2.2.13 kernel on December 18, 1999, to start today's mainline Linux on IBM Z. Formal product announcements quickly followed in 2000, including the Integrated Facility for Linux (IFL) engines. Think Blue Linux was an early mainframe distribution ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
