Patent ID: 8874854

Claim:
A computer-implementable method for disabling and enabling read caching based on past performance of a cache requests comprising: performing a selective read caching function, the selective read caching function selectively enabling and disabling read caching for individual regions of a backstore depending on whether read caching has provided any recent benefit; and wherein while read caching is disabled, a distribution of read accesses to a logical backstore unit (LBU) is recorded over short time intervals, the short time intervals corresponding to a cache residency time value, the cache residency time value comprising a total cache size available for caching divided by a value comprising a read cache miss input/output operation rate for all participating cache multiplied by a ceiling value determined based upon at least an average transfer size, a cache segment size and a number of segments used for cache structures; and, read caching is enabled when one portion of the LBU has more read accesses than other LBUs.