In the capacity planning process, system parameters, desired service levels, and workload predictions are used to determine when the resources of a computer system will be exceeded and are used to assist in identifying cost-effective remedies to resource shortfalls. “Capacity Planning and Performance Modeling: From Mainframes to Client-Server Systems”, by Daniel A. Menasce, Virgilio A. Almedia, and Larry W. Dowdy (Prentice Hall, Englewood Cliffs, N.J., 1994) discloses approaches to both the predicting and rectifying of computer resource challenges.
Capacity planning for a set of heterogeneous computer systems presents several problems, as set forth below. As a first challenge, it must be recognized that workloads use multiple resources. Therefore, the effect of workload assignment is not readily predicted or quantified. Second, workload typically grows, and the rate of growth may differ between resources. Third, different computer systems may have different resources, and different resource capacities. These problems can make it difficult to determine how long available resources will last, which computer systems are most at risk for exceeding their resources, how to reallocate resources to alleviate shortages, and how the computer systems will be affected by such reallocations.
Dan Asit and Dinkar Sitaram, in U.S. Pat. No. 5,530,557, entitled “Online Placement of Video Files Determined by a Function of the Bandwidth to Space Ratio of each of the Storage Device in a Server Environment”, (Jun. 25, 1996) teach one solution for maximizing storage utilization for the placement of videos on storage devices taking into account the expected demand for the video. Asit, et al use the bandwidth space ratio (BSR) to place videos on disks. The BSR of a disk is its bandwidth divided by space. The BSR of a video is the expected demand for the video divided by the space required to store it. Deman may be forecast based on historical usage data and, in their invention, a Video Placement Manager places the videos on the disks to match the BSR of the videos with the BSR of the disk.
Additional references which have sought to predict and manage storage capacity include an article and related patent application of W. G. Pope and Lily Mummert. The article entitled “The Use of Life Expectancy to Manage Notes Domino E-Mail Storage”, Proceedings of the Computer Measurement Group, CMG '99, December 1999, and the patent application Ser. No. 09/457,467 entitled “System and Method for Providing Property Histories of Objects and Collections For Determining Device Capacity Based Thereon”, which was filed on Dec. 8, 1999, propose a method for projecting device capacity by past history of access to and usage of the relevant information for a single computer system.
What is still needed however, and what is an objective of the present invention, is a method for analyzing capacity constraints for multiple resources of a plurality of computer systems.
Another objective of the present invention is to identify critical system limitations which may then be targeted in reallocating resources to alleviate shortages.