Patent ID: 8380666

Claim:
A file system management device connectable to a storage device, the storage device comprising a first file system entity created according to a first file system in which a second file system entity created accordingto a second file system is allowed to be mapped, wherein a mapping information storing area is defined on a predetermined area of the first file system entity, the mapping information storing area being reserved for storing mapping information indicating a correspondence of the mapping, the file system management device comprising: an interface configured to connect the file system management device to the storage device via a direct local connection that does not include any intervening network elements; and an accessing unit configured to access the second file system entity based on the mapping information stored at the mapping information storing area defined on the predetermined area of the first file system entity through a process according to the first file system to the first file system entity, the first file system entity comprising an attribute area reserved for storing attribute information of the first file system entity and the attribute area comprises the mapping information storing area, wherein the storage device disables a writing or erasing operation of the first file system entity having the second file system entity mapped therein when an operation under the first file system is received from the file system management device, disables a writing or erasing operation of the attribute information of the first file system entity according to the first file system during an initial activation of the storage device, allows the writing or erasing operation of the attribute information when an access to the second file system entity according to the second file system is received, and disables the writing or erasing operation of the attribute information when the access to the second file system is finished.