Varying data redundancy in storage systems

摘要

A disk drive is disclosed that varies its data redundancy policy for caching data in non-volatile solid-state memory as the memory degrades. As the non-volatile memory degrades, the redundancy of data stored in the non-volatile memory can be increased to counteract the effects of such degradation. Redundant data can be used to recover data stored in the non-volatile memory in case of a data corruption. Performance improvements and reduced costs of disk drives can thereby be attained.

主权项

1. A data storage system comprising:
a non-volatile solid-state memory configured to store data; and a controller configured to store data in the non-volatile memory, the controller further configured to: determine a reliability measurement of the non-volatile memory; in response to comparing the reliability measurement to at least one reliability threshold, determine a parity level or a mirroring level of the non-volatile memory and set a redundancy level of the non-volatile memory to the determined parity level or the determined mirroring level, the controller being further configured to increase at least one of the parity or the mirroring level when the reliability measurement has been determined to decrease when compared to the at least one reliability threshold; and store the data in the non-volatile memory using the set redundancy level; and wherein increasing the mirroring level comprises increasing a number of copies of the data in a plurality of copies of the data stored in the non-volatile memory, and wherein increasing the parity level comprises increasing a number of parity data units in a plurality of parity data units associated with the data, the plurality of parity units stored in the non-volatile memory along with the data.