Abstract: Write operations less than full block size (short block writes) are internally accumulated while being written to disk in a temporary cache location. Once written to the cache location, the disk drive signals the host that the write operation has completed. Accumulation of short block writes in the drive is transparent to the host and does not present an exposure of data loss. The accumulation of a significant number of short block write operations in the queue make it possible to perform read/modify/write operations with a greater efficiency. In operation, the drive preferably cycles between operation in the cache location and the larger data block area to achieve efficient use of the cache and efficient selection of data access operations. In one embodiment, a portion of the disk surface is formatted at a smaller block size for use by legacy software.

Abstract: A clustering storage system, which enables to operate a plurality of storage system units as a single storage system, presents connection information between clustering storage systems to a user and receives data to be backed up and an instruction about a path between the clustering storage systems from the user. The clustering storage system uses load information or a transfer speed of a data connection line between the storage system units to determine a path between the clustering storage systems used for backup and a storage system unit for holding a backup copy so that the data transfer between the storage system units becomes minimum. Besides, the clustering storage system mainly uses the determined path for backing up the data.

Abstract: A method of supporting programs that include instructions that modify subsequent instructions in a multi-processor system with a central processing unit including an execution unit, and instruction unit and a plurality of caches including a separate instruction and operand cache.

Abstract: Tables (FIGS. 11 and 12) for stipulating information (WWN: WorldWide Name) for primarily identifying computers, information (GID: Group ID) for identifying a group of the computers and a logical unit number (LUN) permitting access from the host computer inside storage subsystem, in accordance with arbitrary operation method by a user, and for giving them to host computer. The invention uses management table inside the storage subsystem and gives logical unit inside storage subsystem to host computer group arbitrarily grouped by a user in accordance with the desired form of operation of the user, can decide access approval/rejection to the logical unit inside the storage subsystem in the group unit and at the same time, can provide the security function capable of setting interface of connection in the group unit under single port of storage subsystem without changing existing processing, limitation and other functions of computer.