GARBAGE COLLECTION TECHNIQUES FOR A DATA STORAGE SYSTEM

A technique for garbage collection in a data storage system includes determining a dirty physical byte count for each of a plurality of candidate garbage collection units. The dirty physical byte count provides a total amount of dirty bytes. At least one of a dirty physical codeword container count and a dirty physical page count is determined for each of the candidate garbage collection units. The dirty physical codeword container count provides an amount of physical codeword containers that are completely dirty and the dirty physical page count provides an amount of physical pages that are completely dirty. A garbage collection unit, included in the candidate garbage collection units, is selected for garbage collection based on the dirty physical byte count and at least one of the dirty physical codeword container count and the dirty physical page count.