Unisys Corporation

Joseph E Kessler

Robert E Swenson

Craig B Johnson

Dennis R Konrad

Ralph E Sipple

Thomas P Cooper

Michael J Hill

Michael J Heideman

James F Torgerson

Carl R Crandall

James W Adcock

Haeng D Park

John R Jordan

Michael C Otto

Thomas N DeVries

Kathleen Georgia Elliot

Anthony P vonArx

Kenneth L Willis

Robert S Yach

Robert F Esson

Donald T Bordsen

A system and method for processing I/O requests in a computing system. I/O packets are created via an operating system associated with the computing system, where the I/O packets include I/O transaction information. The I/O packets are made accessible to an I/O system. A command for a channel type connecting a target I/O component to the I/O system is constructed, where this command construction is based on the I/O transaction information provided in the I/O packet, and based on physical aspects of the target I/O component and channel type provided independently of the I/O packet. The constructed command is issued to the target I/O component in accordance with the channel type.

System and method for facilitating use of commodity I/O components in a legacy hardware system

An outboard file cache system including file surge protection and an improved method for managing allocation of cache storage are disclosed. In an outboard cache, excessive writes to a file are detected by testing whether a segment belonging to a file specified by a nd, which logically precedes one of the segments specified in the command by a predetermined number of segments, is present in the outboard file cache, has been written, and has not been destaged. When a first surge-threshold is reached, a group of segments is selected and destaged. When a second surge-threshold is reached, the outboard cache inhibits allocation of further cache storage for the file for the purpose of writing until a selected group of segments is destaged.

Cache system with file surge protection and method for managing

A multiprocessor data processing system is implemented with processors, each of which may request for a temporary time the exclusive lock on an object which is stored on a data base. To achieve this a lock processor synchronizes the locking and unlocking of the objects. The requesting processor directs the storage of the object from the data base into a selected high performance storage unit, where it has exclusive rights to modify or write into the object until the object is unlocked by the processor. An audit tape or disk records all modifications made to any object during a transaction. A non-volatile cache memory is inserted in the audit trail to store a before-look image of the object that resides in the high performance storage unit. Data compaction occurs by comparison of the before-look image with an after-look image to provide a difference image, which is supplied to an audit buffer that is coupled to the audit tape. The locking processor may unlock the secured object once the after-look image has been committed from either a stored version in the non-volatile cache or from a high performance main memory unit to the data base disk. The difference image and the after-look image associated with the difference image may then be stored in the non-volatile cache, and provided to the audit tape or disk and the data base disk in a sequence which is independent of the operating sequence of the requesting processor.

Cache memory with data compaction for use in the audit trail of a data

A procedure, enabled in software, and applied to a cache/disk environment controlled by a host computer operating through a Block Multiplexor Channel Interface and Storage Control Unit, functions to use FIPS 97 and FIPS 60 protocols to execute data transfers between host processors and a plurality of disks whereby simultaneous operations can function with up to 16 disk units. Up to seen I/O requests can be queued on each of the 16 disk units while the system can normally operate in the cache/disk mode. Additionally, the system can operate in the disk-only mode or storethrough mode.

FIP-compliant block multiplexor channel interface operational method for

Growing community of inventors

St. Anthony, MN, United States of America

Joseph E Kessler