A technique for garbage collection in a storage system includes generating regrouping metadata for one or more pages of at least two logical erase blocks (LEB). The regrouping metadata indicates an associated stream for each of the pages. Multiple of the LEBs that include valid pages associated with a first stream are selected, based on the regrouping metadata, for regrouping. The valid pages associated with the first stream from the selected LEBs are regrouped into a new LEB.