International Business Machines Corporation

Marten J Halma

Kenneth J Oakes

Leslie W Wyman

Harry M Yudenfriend

Charles E Shapley

Charles W Gainey, Jr

Jeffrey Paul Kubala

Steven G Glassen

Frank William Brice

Tan Lu

Daniel Francis Casper

Frank David Ferraiolo

John S Trotter

Allan Samuel Meritt

Robert S Capowski

Hans-Helge Lehmann

Janet R Easton

Beth A Glendening

Eugene P Hefferon

Roger E Hough

Martin W Sachs

Kenneth J Fredericks

Suzanne M John

Robert Edward Galbraith

Scott M Carlson

Derrick LeRoy Garmire

Christine M Desnoyers

Robert Frederick Stucke

Frederick J Cox

James C Mazurowski

David W Hollar

Thomas Anthony Gregg

Dale Francis Riedy, Jr

Gustav E Sittmann, Iii

James T Brady

Thomas Edward Cook

Joseph C Elliott

Carol B Hernandez

David E Stucki

Richard Roland Guyette

Robert E Murray

Richard Cwiakala

Frank W Brice

Assaf Marron

Francis E Johnson

Juergen Erwin Maergner

Wolfgang Eckert

John C Rathjen, Jr

Robert A Smith

Ugochukwu Njoku-Charles

Paul A Malinowski

Sandra Kay Ryan

Thomas H Hillock

Benjamin Hong Wu

Ugochukwo Njoku-Charles

Michael G Melendy

Miriam P Brown

An input/output subsystem is configured as a plurality of input/output subsystem images, each of which appears to a program as an independent input/output subsystem. An input/output subsystem image is identified by an input/output subsystem image identifier, which is used by various programs to designate the particular input/output subsystem image for which an I/O operation is to be performed. An input/output subsystem image includes, for instance, one or more input/output paths. An input/output path of an input/output subsystem image is identified by an input/output path identifier, as well as a physical input/output path identifier.

Multiple logical input/output subsystem facility

An input/output subsystem is configured as a plurality of input/output subsystem images, each of which appears to a program as an independent input/output subsystem. In response to an operating system image submitting an input/output (I/O) request requesting access to an input/output subsystem image, a determination is made as to whether the operating system image is authorized to access the input/output subsystem image. In response to the access being authorized, the I/O request is authorized.

Managing access, by operating system images of a computing environment, of input/output resources of the computing environment

A communications adapter is shared by a plurality of input/output (I/O) subsystem images of an I/O subsystem of a central processing complex. To enable the sharing, the communications adapter is configured to a plurality of I/O paths of the plurality of I/O subsystem images. An I/O subsystem may have one or more shared communications adapters.

Sharing communications adapters across a plurality of input/output subsystem images

An input/output subsystem of a computing environment is configured as a plurality of input/output subsystem images, each of which appears to a program as an independent input/output subsystem. An input/output subsystem image includes one or more communications adapters used for communicating within the computing environment. A communications adapter is identified by hardware of the computing environment by using a first identifier, and it is identified by a program of the computing environment by using a second identifier. The identifiers can be of different sizes.

Method, system and program products for identifying communications adapters of a computing environment

An input/output subsystem is configured as a plurality of input/output subsystem images, each of which appears to a program as an independent input/output subsystem. One or more input/output subsystem images of the plurality of input/output subsystem images are managed. An aspect of this management includes managing an input/output (I/O) configuration of an input/output subsystem image. This management may be performed dynamically.

Managing configurations of input/output system images of an input/output subsystem, wherein a configuration is modified without restarting the input/output subsystem to effect a modification

An input/output subsystem is configured as a plurality of input/output subsystem images, each of which appears to a program as an independent input/output subsystem. An input/output subsystem image is identified by an input/output subsystem image identifier, which is used by various programs to designate the particular input/output subsystem image for which an I/O operation is to be performed. An operating system is provided with access to a plurality of input/output subsystem images of the input/output subsystem. One or more controls are provided to the operating system image to enable the operating system image to access the plurality of input/output subsystem images.

Method, system and program products for enhancing input/output processing for operating system images of a computing environment

The utilization of various individual components of a channel is determined in order to learn which portion of a channel is busy and to what extent that portion is busy. The determination of a component's utilization is dependent on the type of component, as well as the operational characteristics of that component.

Measuring utilization of individual components of channels

An attached storage media link has a self-timed interface (STI) in which a clock signal clocks bit serial data onto a parallel, electrically conductive bus and the clock signal is transmitted on a separate line of the bus. The received data on each line of the bus is individually phase aligned with the clock signal, providing a high speed, cost effective interface to a direct access storage device.

Self-timed parallel data bus interface to direct storage devices

A massively parallel system has a self-timed interface (STI) in which a clock signal clocks bit serial data onto a parallel, electrically conductive bus and the clock signal is transmitted on a separate line of the bus. The received data on each line of the bus is individually phase aligned with the clock signal. Digital data is transmitted at high speeds via the parallel bus to provide a scalable communications network for parallel processing systems while eliminating precise bus length and system clock rates as a critical or limiting factor.

Synchronous interface for transmitting data in a system of massively parallel processors

A computer system and processing method are provided for coupling multiple physical processing nodes together, wherein each physical processing node is characterized as having its own memory, by either at least one channel which is independent of and coupled to the multiple physical processing nodes or by at least one input/output (I/O) processor, again which is independent of and coupled to the multiple physical processing nodes. The at least one channel and/or the at least one I/O processor couple the multiple physical processing nodes to at least one shared input/output device. Sharing of the at least one channel and/or at least one I/O processor is practical by providing 'indirect logical addressing' using logical address tables within the channel subsystem. The logical address tables associate an image identifier (Image.sub.-- ID) and processing node identifier (PN.sub.-- ID) concatenation with an indexed logical address for use in communicating I/O operation parameters across the at least one channel.

Independent channel coupled to be shared by multiple physical processing

Self-timed interface for a network of computer processors interconnected

Automatic machine methods and apparatus for determining which components of an I/O configuration are shared by other components of the configuration. The information can be obtained through the use of existing self-description facilities and unique identifiers. By noting which channel paths are used to obtain configuration-data records and examining the unique identifiers provided for each I/O items it can be determined which I/O devices are accessible through the same control unit, and which control units provide access to the same I/O device. Furthermore, by examining the unique identifiers provided, it can be determined which I/O subsystems and which control units or channel subsystems are accessible through the same dynamic switch and which dynamic switches provide access to the same I/O subsystem of channel subsystem. A programmable subchannel is provided to enable communication between a CEC and an electrically-connected I/O item not represented in the current I/O configuration description being used by the CEC. Without the programmed subchannel, the CEC cannot access any I/O item not represented in the CEC's current I/O configuration description.

Method and apparatus for automatic generation of I/O configuration

A method and system to eliminate service hardware previously provided with an adapter by providing a novel way to transfer its hardware service functions to a remote service hardware found elsewhere in a computer system, such as a mainframe. The transferred service controls include enabling the remote service hardware to control the updating of the adapter microcode; remotely control a recovery process for the adapter by remotely initializing its microcode, and remotely logging out and recovering from error conditions detected in the adapter; and remotely forcing a logout and recovery when the host OS detects a failure in the adapter. A standard I/O channel interface (optical or electronic) is provided between the adapter and an IOSS (Input Output Subsystem) of a computer system which has its own service processor element (SPE) used for servicing the computer system per se. The invention provides virtual service hardware for the adapter, but uses the SPE for its service hardware. The SPE is remote from the adapter in the sense that the SPE and the adapter can only communicate with each other over the standard I/O channel interface. The servicing functions required by the adapter are transferred to, and handled by, the SPE by internal I/O facilities (iIOF) provided in the IOSS, which change the internal subchannel architecture of the IOSS.

Method and system for controlling servicability of adapters connected by

An Internal I/O Facility (iIOF) having a general interface for executing I/O related applications in an Input/Ouput SubSystem (IOSS) of a computer system. IIOF applications are executed in the IOSS outside the scope of CPU applications executed under the operating system (OS) of the computer system. IIOF applications are allowed to use all facilities in the IOSS. An iIOF subchannel extension is provided for those subchannels which can execute an iIOF application. IIOF subchannel extensions contain interception control fields which determine if conventional processing for the subchannel by the IOSS is to be intercepted to execute an iIOF application. A front-end interception bit in a subchannel extension is used to initiate iIOF application execution when the subchannel is taken from the IOSS work request queue. A back-end interception bit in a subchannel extension is used to initiate iIOF application execution when the subchannel is to have status put on the IOSS interruption queue. The iIOF application is defined in a field in the iIOF subchannel extension. The IOSS may front-end intercept I/O requests made by the OS, and the IOSS may back-end intercept status received by the IOSS for I/O interruptions to be generated by the IOSS.

Method and system for superimposing, creating and altering I/O

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Poughquag, NY, United States of America

Marten J Halma