Patent ID: 8463989

Claim:
A storage device comprising: a communication port configured to communicate with a host computer; a block access processing unit configured to process a block access request which is an input request per block from the host computer; disk devices comprising multiple logical units; and a memory configured to store session management information, including: (i) first information which indicates user IDs for identifying users of the host computer, (ii) second information which indicates logical units accessible by users identified by one of the user IDs, (iii) third information which indicates whether an iSCSI session corresponding to the logical units is established, (iv) fourth information which indicates whether file accesses to the logical units are possible by the user identified by the one of the user IDs, and (v) fifth information which indicates whether the logical units are already mounted, wherein when the communication port receives a login request for block access according to the iSCSI protocol from the host computer, the block access processing unit is configured to use the session management information to specify a logical unit as an access target, to unmount the specified logical unit, to set the third information to a value indicating that the iSCSI session has been established, to set the fifth information to a value indicating that the specified logical unit is not mounted, and to perform block access processing, when the communication port receives a logout request for block access according to the iSCSI protocol from the host computer, the block access processing unit is configured to determine whether a mount operation has been successfully completed by attempting to mount the specified logical unit including a file written by the block access processing, if the mount operation has been successfully completed, the block access processing unit is configured to change the third information to a value indicating that the iSCSI session has not been established and to change the fifth information to a value indicating that the specified logical unit is mounted to put the specified logical unit in a state where file access is possible, and, if the mount operation has not been successfully completed, the block access processing unit is configured not to change the values of the third and fifth information.