| 摘要 |
<p>PROBLEM TO BE SOLVED: To achieve a monitor system capable of allowing a quick promotion for an increase in the number of I/Os of a specific page while suppressing a demotion due to a temporary decrease in the number of I/Os of the specific page at a point of view of a long period, because a promotion in a short period cannot be performed when a measuring period of a monitor is set to the long period, and a page is promoted after waiting for several weeks even if the number of I/Os is very large, for variations in the number of I/Os in the unit of from several minutes to several hours in a normal job, and then I/O of several weeks which should be received originally by an upper hierarchy is received by a lower hierarchy to reduce performance efficiency.SOLUTION: A load index value specified at a point of view of a long period and a load index value specified at a point of view of a short period are updated by the number of I/Os for each storage area which is counted periodically. A promotion or a demotion is performed on the basis of a value calculated from these load index values.</p> |
