Patent ID: 8311992

Claim:
An information processing system that receives a data Input/Output (I/O) request in units of files, and performs writing or reading of data to/from a storage system that includes a non-transitory computer readable storage medium storing therein a file entity specified as the data I/O request received in units of data blocks, the information processing system comprising: a processing part, during shredding of a specific data block of the non-transitory computer readable storage medium, selecting a file whose update frequency exceeds a preset threshold value from files stored in the non-transitory computer readable storage medium, and performing pseudo shredding on the data block by storing a selected file entity in the data block; a processing part receiving a request to implement shredding in units of files and writes data for shredding on the data block storing a file entity specified by the implementation request received, and starting the pseudo shredding on the data block that is a target of the data write request in a processing wait status when detecting that a number of the shredding implementation request in queue or an increase thereof exceeds a preset threshold value; a processing part storing a directory entry wherein correspondence between a file path name and an inode number is managed, and an inode management table wherein correspondence between an inode number and a data block is managed, acquiring an inode number that corresponds to a specified file path name from the directory entry when the shredding implementation request therefore is received, and acquiring a data block that corresponds to the acquired inode number from the inode management table and writing the data for shredding on the acquired data block; a processing part storing into a separate data block that is not a target of a writing process for shredding the selected file entity, used for the pseudo shredding, stored in a data block and updates the inode management table to correspond to a post storing state, at the time data write processing for the shredding, in a case the pseudo shredding is started on the data block that is a target of the write processing; and a processing part storing into a separate data block that is not a target of a writing process for shredding a file entity, used for the pseudo shredding, stored in a data block and performs write processing of data for shredding on the separate data block, at the time data write processing for the shredding, in a case the pseudo shredding is started on the data block that is a target of the write processing, wherein data writing for the shredding on a data block is not performed, in a case a number of updates of the data block that is a target of the pseudo shredding exceeds a preset threshold value after the pseudo shredding has started.