International Business Machines Corporation

Gary A Fisher, Sr

Robert O Dryfoos

Eugene P Hefferon

Martin W Sachs

David B Flaxer

Richard Cwiakala

Robert A Blackburn

Karl H Hoppe

Glenn W Sears, Jr

Robert J Gallagher

Michael C Cox

Loraine Arnold

Peter I Kania

Jean-Louis Fava

An exemplary embodiment of the present invention is a method for dynamically managing a hash pool data structure. A request to insert a new key value into a hash pool data structure that includes at least one index level is received. An insertion location is calculated for the new key value in response to the new key value and to existing key values in the hash pool data structure. The insertion location includes an index level. A new index level is added at the insertion location if the index level is not the maximum number of index levels in the hash pool data structure; if the insertion location contains a chain of existing key values with a length equal to the maximum chain length; and if the new index record locations of the new key value and the existing key values are dispersed. The insertion location is updated in response to adding a new index record and the new key value is inserted into the insertion location. An additional embodiment includes a system and storage medium for dynamically managing a hash pool data structure.

Method and system for dynamically managing hash pool data structures

A computer system, including at least one host (processor and operating system), a channel subsystem and at least one switch (together with an associated switch controller) for switchably connecting an I/O device (together with an associated I/O device control unit) to a host via said channel subsystem, in combination with means for dynamically managing I/O connectivity in said computer from each host. The I/O manager's functions are centralized at the host level across the computer system. Each host is responsible for an instance of the manager. According to the preferred embodiment of the invention the computer system, I/O manager combination includes: (a) first means, located within each switch, for providing direct host access to the switch controller associated with a given switch; (b) second means, included in each host level instance of the manager, for automatically and dynamically determining the current I/O configuration and connectivity of each host; (c) third means, included in each host level instance of the manager, for performing System Integrated Switching (i.e., switching where any instance of the I/O manager can veto a proposed configuration change) and (d) fourth means, included in each host level instance of the manager, for insuring the integrity of the I/O connectivity database, through the use of an interlock mechanism, in a multiuser environment where each user can enter multiple part commands and processes concurrently.

Methods and apparatus for dynamically managing input/output (I/O)

A method of creating a data structure or map describing the I/O configuration and of verifying and resolving errors in configuration data in a system in which processors are coupled to one another or to device control units either directly or through a dynamic switch by way of links attached to link adapters of respective end units. Each pair of unit link adapters coupled to the respective ends of a link exchanges information identifying the unit and the adapter on that unit. A physical configuration map indicating the actual physical system configuration is constructed from such 'nearest neighbor' information. This physical configuration map is compared with a logical configuration map indicating the user-defined logical system configuration to determine the existence of any discrepancies therebetween, and one map is conformed to the other as appropriate.

Method and apparatus for verifying the configuration of a link-connected

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Port Ewen, NY, United States of America

Gary A Fisher, Sr