Abstract: Upon receiving an access request from a server, a microprocessor allocates a free slot as a data storage destination that is different from the LU# and LBA designated as a storage destination of user data, stores user data and data identifying information for identifying the user data in the free slot, and zero-clears the pre-updated data slot designated with the LU# and LBA. During a subsequent read access, the microprocessor accesses the data slot and, if the read data identifying information and the data identifying information designated in the read access from the server coincide, transfers this read data to the server as correct data, and, if the read data identifying information and the data identifying information designated in the read access from the server do not coincide, performs processing for recovering correct data based on the read data identifying information.

Abstract: In a storage apparatus comprising a communication interface that receives an I/O request sent from a host apparatus, a storage device controller that performs writing and reading of data with respect to a storage device, and a cache memory that stores data to be written in the storage device or data read from the storage device, a journal volume operated as a volume for which update writing is prohibited and write once is permitted is provided, on the basis of a storage area provided by the storage device, and a virtual volume is provided as a volume accessible from the host apparatus, the journal volume being the entity of the virtual volume, the virtual volume being a volume for which an attribute (Read/Add) that permits only reading and write once is settable.

Abstract: In a storage apparatus comprising a communication interface that receives an I/O request sent from a host apparatus, a storage device controller that performs writing and reading of data with respect to a storage device, and a cache memory that stores data to be written in the storage device or data read from the storage device, a journal volume operated as a volume for which update writing is prohibited and write once is permitted is provided, on the basis of a storage area provided by the storage device, and a virtual volume is provided as a volume accessible from the host apparatus, the journal volume being the entity of the virtual volume, the virtual volume being a volume for which an attribute (Read/Add) that permits only reading and write once is settable.

Abstract: Upon receiving an access request from a server, a microprocessor allocates a free slot as a data storage destination that is different from the LU# and LBA designated as a storage destination of user data, stores user data and data identifying information for identifying the user data in the free slot, and zero-clears the pre-updated data slot designated with the LU# and LBA. During a subsequent read access, the microprocessor accesses the data slot and, if the read data identifying information and the data identifying information designated in the read access from the server coincide, transfers this read data to the server as correct data, and, if the read data identifying information and the data identifying information designated in the read access from the server do not coincide, performs processing for recovering correct data based on the read data identifying information.