Patent ID: 8756387
Filing Date: 2014-06-17
Classification: G06F

Abstract:
1. A storage system for processing READ and WRITE requests from an external host, the storage system comprising: (A) a FLASH storage system configured as a primary storage space for the storage system; (B) a backup hard drive storage system configured to back up data stored on the FLASH storage system, the backup hard drive storage system having a storage space that is an integer factor less than the storage space of the FLASH storage system and divided into a plurality of blocks; and (C) a storage controller configured to receive READ and WRITE requests from an external host, the storage controller being coupled to the FLASH storage system and the backup hard drive storage system such that the storage controller can issue READ and WRITE requests to both the FLASH storage system and the backup hard drive storage system, wherein the storage controller is configured to: (i) receive a WRITE request from an external host, the WRITE request containing data and an address corresponding to a location where such data is to be stored and: (ii) receive a READ request from an external host, the READ request containing an address corresponding to a location from which data is to be read and: (iii) identify one or more alternative addresses to be compacted in the backup hard drive storage system that are out of sequence for a next alternative WRITE operation and contain stale or invalid data, and: