AVAILABLE-SPACE MANAGEMENT METHOD FOR NONVOLATILE MEMORY, ACCESS DEVICE WHICH STORES DATA TO INFORMATION STORAGE DEVICE WITH NONVOLATILE MEMORY, INFORMATION STORAGE DEVICE, AND INFORMATION STORAGE SYSTEM

摘要

Provided is a method of managing space available on an information storage device, by means of an access device that accesses an information storage device having a nonvolatile memory for storing file data. When the information storage device is mounted on the access device: available-space management information, used to manage the space available in each storage region of a prescribed length, is loaded from the information storage device (S14); the available-space management information is rebuilt on the basis of the state of data storage in the nonvolatile memory (S15); and the available-space management information is updated in response to a data write to the nonvolatile memory (S18). When the information storage device is unmounted, the available-space management information is stored on the information storage device (S23).