The present invention is directed to an SSD that stores data in a plurality of regions of the SSD, each of the regions associated with a plurality of logical cluster addresses. The SSD also sets a deallocation status of each of the plurality of regions in a deallocate flag bitmap and sets a deallocation status of one or more sections of the deallocate flag bitmap in a deallocate summary table, wherein each of the one or more sections corresponds to more than one of the plurality of regions. In response to a shutdown or loss of power event. The SSD writes to non-volatile memory only sections of the deallocation flag bitmap with a predetermined deallocation status in the deallocate summary table. The SSD stores the deallocate flag bitmap is stored in a first volatile memory and stores the deallocate summary table is stored in a second volatile memory, different from the first volatile memory.