International Business Machines Corporation

Jessica M Gisi

Robert Edward Galbraith

Carl E Forhan

Donald J Ziebarth

Steven Paul Norgaard

Dennis David Reetz

Daniel Frank Moertl

Timothy J Schimke

Brian Eric Bakke

Paul Gary Reuland

Frederic Lawrence Huss

Russell Paul VanDuine

Lawrence P Connoy

Douglas David Prigge

A low complexity approach to DASD cache management. Large, fixed-size bands of data from the DASD, rather than variable size records or tracks, are managed, resulting in reduced memory consumption. Statistics are collected for bands of data, as well as conventional LRU information, in order to improve upon the performance of a simple LRU replacement scheme. The statistics take the form of a single counter which is credited (increased) for each read to a band and penalized (reduced) for each write to a band. Statistics and LRU information are also collected for at least half as many nonresident bands as resident bands. In an emulation mode, control information (e.g., statistics and LRU information) regarding potentially cacheable DASD data, is collected even though there is no cache memory installed. When in this mode, the control information permits a real time emulation of performance enhancements that would be achieved were cache memory added to the computer system. Dynamic reconfiguration of the cache size is also permitted in real time without requiring computer system downtime.

Advanced read cache management

A method for maintaining data coherency in a dual Input/Output(I/O) adapter having primary and secondary adapters, wherein each of the primary and secondary adapters includes resident write cache data and directory storage devices. The method includes utilizing a split point to separate each of the cache data and directory storage devices into first and second regions, wherein the first regions contain the primary adapter cache data and directory information and the second regions contain the secondary adapter cache data and directory information. Information stored in the primary adapter cache data and directory storage devices is mirrored into the secondary adapter cache data and directory storage devices or, alternatively, information stored in the secondary adapter cache data and directory storage devices is mirrored into the primary adapter cache data and directory storage devices utilizing a dedicated communication link, such as a high-speed serial bus, between the primary and secondary adapters.

Method and system for maintaining data coherency in a dual input/output adapter utilizing clustered adapters

A low complexity approach to DASD cache management. Large, fixed-size bands of data from the DASD, rather than variable size records or tracks, are managed, resulting in reduced memory consumption. Statistics are collected for bands of data, in order to improve upon the performance of a simple LRU replacement scheme. The statistics take the form of a single counter which is credited (increased) for each read to a band and penalized (reduced) for each write to a band. Statistics and LRU information are also collected for at least half as many nonresident bands as resident bands. In an emulation mode, control information (e.g., statistics and LRU information) regarding potentially cacheable DASD data, is collected even though there is no cache memory installed. When in this mode, the control information permits a real time emulation of performance enhancements that would be achieved were cache memory added to the computer system. Dynamic reconfiguration of the cache size is also permitted in real time without requiring computer system downtime.

Advanced read cache emulation

A computer program is provided. The computer program product includes a medium readable by a computer, the medium (1) having means for inputting a signal representative of a temperature range in which a temperature of an operating environment of a battery resides; and (2) means for estimating a service life of the battery based on the signal. Other means are also provided.

Method and apparatus for estimating the service life of a battery

An apparatus is provided for estimating the service life of a battery. The apparatus includes a temperature measurement circuit that measures a temperature of an operating environment of the battery and outputs a signal representative of the temperature of the operating environment. A controller coupled to the temperature measurement circuit receives the temperature signal therefrom and estimates the service life of the battery based on the temperature signal. Preferably, the temperature measurement circuit outputs a signal representative of a temperature range in which the measured operating environment temperature resides and the controller estimates the service life of the battery based on the temperature range signal output by the temperature measurement circuit. A method and a computer program product also are provided for similarly estimating the service life of a battery.

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Rochester, MN, United States of America

Jessica M Gisi