Memory system and information processing system

According to one embodiment, a memory system includes a non-volatile memory and a data map configured to manage validity of data written in the non-volatile memory. The data map includes a plurality of first fragment tables corresponding to a first hierarchy and a second fragment table corresponding to a second hierarchy higher than the first hierarchy. Each of the first fragment tables is used to manage the validity of each data having a predetermined size written in a range of physical address in the non-volatile memory allocated to the first fragment table. The second fragment table is used for each of the first fragment tables to manage reference destination information for referencing the first fragment table.