US Patent 12007967 Deduplication database without reference counting

A deduplicated storage system is provided according to certain embodiments that uses one or more mechanisms to update the deduplication database and remove records corresponding to data blocks that have been or will be erased from the secondary copies, without using or tracking reference counting values. Some embodiments described herein use a secondary table to identify the corresponding records from the primary table that can be removed and/or moved to another table for storing “zero-reference” data blocks. In other embodiments, the system will then traverse the “zero-reference” table and remove those primary data blocks from secondary storage devices.