Patent ID: 6721814
Filing Date: 2004-04-13
Classification: G06F

Abstract:
An arrangement for use in connection with a host computer connected to a mass storage subsystem, the mass storage subsystem storing information for use in connection with processing of at least one program by the host computer, the arrangement comprising:A. a program input/output interface module configured to receive program input/output read and write requests from a program, each program input/output request initiating an input/output operation in connection with information stored on a mass storage subsystem; B. a mass storage subsystem interface module configured to facilitate communications with the mass storage subsystem, including transferring a storage subsystem input/output request thereto and receiving information therefrom; C. a file system control module configured to, in response to a program input/output read or write request received by the program input/output interface module, generate a storage subsystem input/output read or write request for transmission by the mass storage subsystem interface module to the mass storage subsystem and to transfer information to be transferred during the input/output operation between the program input/output interface module and the mass storage subsystem interface module, and to selectively cache the information in a file system cache maintained by the host computer in relation to the amount of information to be transferred during the input/output operation, and in which the file system control module is configured to determine whether to cache information in relation to the amount of information to be transferred being determined in relation to a mathematical model that models response time in connection with caching by the file system as a function of the amount of information to be transferred during the input/output operation, andin which the file system control module is configured to determine whether to cache information in relation to the amount of information to be transferred being a function of SBLmax&it;Rsupâ€²+RFSC0Î²where (i) Râ€²SUP corresponds to a portion of response time of the mass storage subsystem that does not depend on the amount of information that is to be stored or retrieved by the mass storage subsystem during the input/output operation, and RFSC0 and &bgr; are constants that relate the amount of information to be transferred SBL and RFSC, which corresponds to a contribution of response time for the input/output operation corresponding to the time to store information in the file system cache during a storage operationRFSC=RFSC0+&agr;â€²SBL+&bgr;â€²SBL2.