Patent ID: 8650368

Claim:
A method for controlling a reduced redundancy storage system to selectively transfer the contents of an index entry write buffer associated with the reduced redundancy storage system to a subblock index associated with the reduced redundancy storage system, comprising: configuring a bitfilter associated with the subblock index with information sufficient to correctly report that a subblock is not present in the reduced redundancy storage system; accessing a subblock to be considered for inclusion in the reduced redundancy storage system; upon determining that the bitfilter indicates that the sublock to be considered is not known to the reduced redundancy storage system: selectively storing an index hash value associated with the subblock to be considered in the subblock index entry write buffer, where the subblock index entry write buffer is located in a first storage area accessible to the reduced redundancy storage system, the first storage area having a faster access time than a second, different storage area; and updating the bitfilter with information sufficient to correctly report that the subblock to be considered is known to the reduced redundancy storage system; and upon determining that a property of the sublock index entry write buffer has exceeded a threshold, selectively transferring the contents of the index entry write buffer to the subblock index, where the subblock index is located in the second, different storage area accessible to the reduced redundancy storage system, and where the index entry write buffer is divided into a plurality of portions corresponding to portions of the subblock index.