Method and system of storing data to data storage for variable size deduplication

Abstract

A method of storing data to a data storage and related device are provided, wherein data storage is divided into two or more variable size chunks, and each variable size chunks is divided into blocks, and the data storage comprises set of metadata. The data storage is also divided into two fixed size chunks. The method comprises: writing incoming write IO to a position of the corresponding size chunk in the data storage; setting the change indicator for the corresponding fixed size chunk to indicate that the corresponding fixed size chunk has been changed since it was divided into variable sized chunks. When change indicators indicate that division of the associated fixed size chunk or chunks into variable sized chunks should be changed, rechunking fixed size chunk into variable sized chunks is executed. Because of the change indicator, high deduplication is maintained even for offline deduplication in the data storage.