A writing method of a storage system which includes a host and a storage connected to the host, includes receiving journal data during a generation of a data writing transaction; inserting in a first map table, a plurality of entries, each entry including a first logical address of a first logical area of the storage and a second logical address of a second logical area of the storage; writing the journal data to a physical area of the storage corresponding to the first logical address; and remapping the physical area from the first logical address onto the second logical address using the plurality of entries when a size of a usable space of the first logical area is less than a desired value.