Storage system cache using flash memory with direct block access

Abstract

Embodiments of the invention enable a storage cache, comprising flash memory devices, to have direct block access to the flash such that the physical block addresses are presented to the storage system's cache layer, which thereby controls the storage cache data stream. An aspect of the invention includes a caching storage system. The caching storage system comprises a plurality of flash memory units organized in an array configuration. Each of the plurality of flash memory units includes at least one flash memory device and a flash unit controller. Each flash unit controller provides the caching storage system with direct physical block access to its corresponding at least one flash memory device. The caching storage system further comprises a storage cache controller. The storage cache controller selects physical block address locations (within a flash memory device) to be erased where data are to be written, issues erase commands to a flash unit controller corresponding to the selected physical block address locations, and issues page write operations to a set of erase blocks.