A method, computer readable medium storing instructions and system for managing flash memory. Data sector are received and each is written into a data block of a buffer of a non-volatile memory device. Pointers in a data management structure are created for each data sector corresponding to an associated logical block and a storage location of the data sector in the buffer. When a predefined criterion is fulfilled before the buffer becomes full, a number of logical blocks to be merged is determined and data sectors corresponding to the number of logical blocks to be merged are written from the buffer to a primary non-volatile data storage memory of the non-volatile memory device.