Patent ID: 8706997

Claim:
A storage device storing data, the storage device comprising: a device configured to store data in one or more volumes read or written by one or more hosts; a storage device configured to store commands transmitted by the host to acquire information relating to the device, the stored commands including a command storage table for each combination of one of the one or more volumes and one of the one or more hosts; a processor configured to: acquire, for each combination, commands issued to the device when the one or more hosts request access to the data stored in the device and to count a number of issuances per type of command from among the acquired commands; determine, for each combination, whether the counted commands have been previously stored as a command storage table in the storage device, when the counted commands have not been previously stored as a command storage table in the storage device, store the counted commands as a command storage table in the storage device, and, when the counted commands have been previously stored as a command storage table in the storage device, provide a notification; and when receiving the notification, permit the access, on a per host basis, when a type of command and number of issuances of the commands acquired by the processor exactly match the respective type and number of issuances of the commands previously stored as a command storage table in the storage device and reject the access, on a per host basis, when the type of command and number of issuances of commands acquired by the processor do not exactly match the respective type and number of issuances of the commands previously stored as a command storage table in the storage device.