Patent ID: 9292206
Filing Date: 2016-03-22
CPC Classification: G06F

Claim Text:
1. A storage system having backup storage, comprising: a non-volatile memory configured as a primary storage for the storage system and providing a non-volatile storage space for the storage system; a backup hard drive providing a backup storage space for the non-volatile memory, the backup storage space being smaller by an integer factor than the non-volatile storage space and divided into a plurality of blocks; and a storage controller coupled to the non-volatile memory and the backup hard drive, the storage controller being configured to receive a WRITE request from an external host containing data and an address where the data is to be stored, and to write the data contained in the WRITE request to a physical location within the non-volatile memory and a physical location within the backup hard drive, the storage controller additionally configured to write the data contained in the WRITE request to the physical location within the backup hard drive such that WRITE operations to the backup storage space occur sequentially with respect to blocks having stale or invalid data so as to skip over sequential blocks in the backup storage space that have valid data; wherein the storage controller is further configured to receive a READ request from an external host containing an address from which data is to be read, access a physical location within the non-volatile memory corresponding to the address contained in the READ request, and provide data stored at the physical location to the external host in the absence of a READ error message from the non-volatile memory, and to access a physical location within the backup hard drive corresponding to the address received in the READ request and to provide data stored at that address to the host in the presence of a READ error message from the non-volatile memory.