A method, system, and computer program product for multi-generational virtual block compaction comprising identifying a first virtual block, the first virtual block being associated with a first generation number, determining a second virtual block as an appropriate target for live information in the first virtual block, creating an association between the second virtual block and the first virtual block, updating the live information in the first virtual block to be associated with the second virtual block, updating a generation information mapping associated with the first virtual block; and associating a second generation number with the first virtual block.