A method, non-transitory computer readable medium, and device that assists with performing global data deduplication on data blocks across different volumes includes identifying at least two data blocks stored in two or more storage volumes. It is determined whether the at least two data blocks are classified as a shared data block. A new data volume signature is created when the at least two data blocks are determined to be shared. One of the at least two data blocks that are determined to be shared is deleted and the other one of the at least two data blocks and the created signature in one of the two or more storage volumes is stored.