Optimized read cache for persistent cache on solid state devices

Abstract

Systems and methods for a content addressable cache that is optimized for SSD use are disclosed. In some embodiments, the cache utilizes an identifier array where identification information is stored for each entry in the cache. However, the size of the bit field used for the identification information is not sufficient to uniquely identify the data stored at the associated entry in the cache. A smaller bit field increases the likelihood of a 'false positive', where the identification information indicates a cache hit when the actual data does not match the digest. A larger bit field decreases the probability of a 'false positive', at the expense of increased metadata memory space. Thus, the architecture allows for a compromise between metadata memory size and processing cycles.