Storage system and method for prestaging data in a cache for improved performance

A computer-program product for use with a storage system for prestaging data in the system, the computer-program product comprising:

• a computer-readable medium;
• means, provided on the computer-readable medium, for determining a relative change in the frequency of data access for a storage region in the system;
• means, provided on the computer-readable medium, for determining a relative change in the effectiveness of previous prestage operations;
• and
• means, provided on the computer-readable medium, for determining whether to prestage data in the cache and the amount of data to prestage based on the determined relative change in access frequency, the determined relative change in the effectiveness and the size of last I/O access, wherein if the relative change in the frequency of data access and the relative change in the effectiveness are both increasing, then data for the region is prestaged aggressively.

A storage system comprising:

• a cache for prestaging data;
• means for determining a relative change in the frequency of data access for a storage region in the system;
• means for determining a relative change in the effectiveness of previous prestage operations;
• and
• means for determining whether to prestage data in the cache and the amount of data to prestage based on the determined relative change in access frequency, the determined relative change in the effectiveness and the size of last I/O access, wherein if the relative change in the frequency of data access and the relative change in the effectiveness are both decreasing, then data for the region is prestaged minimally.