Abstract: In a storage system capable of making connection to one or more SSDs and capable of controlling inputting and outputting of data to and from a storage region of the SSD, the storage system includes a processor that executes a process. The processor is configured to manage a part of a storage region provided by the one or more SSDs with the same characteristics as a first storage region (performance maintenance region) used to store predetermined data, determine data to be stored in the first storage region in data of which a write access frequency is less than a predetermined value, store the data in the first storage region, and store data determined not to be stored in the first storage region in a second storage region (a normal region) which is different from the first storage region and is provided by the one or SSDs with the same characteristics.

Abstract: It is possible to prevent unoccupied blocks from being depleted by a write of logical-physical management information. A processor is capable of performing an unoccupied user block generation process by moving user data stored in allocated user blocks in order to generate unoccupied user blocks serving as unoccupied blocks among allocated user blocks, and performing an unoccupied meta block generation process by moving meta data stored in allocated meta blocks in order to generate unoccupied meta blocks serving as unoccupied blocks among the allocated meta blocks. The processor calculates the number of unoccupied meta blocks to be consumed, that is, the number of unoccupied meta blocks to be consumed by the unoccupied user block generation process. The processor performs the unoccupied meta block generation process based on the number of unoccupied meta blocks to be consumed.

Abstract: A storage apparatus includes: a controller; and a plurality of storage drives, wherein the controller issues a read command for specifying a value associated with an error correction mode to a first storage drive of the plurality of storage drives, the first storage drive selects the error correction mode associated with the value specified by the read command from a plurality of error correction modes, the plurality of error correction modes include a first error correction mode and a second error correction mode with a higher correcting capability and a longer maximum delay time than those of the first error correction mode, and the first storage drive executes a read of data from a storage medium in the selected error correction mode.

Abstract: A storage apparatus includes: a flash memory that provides a storage area; a controller that controls writing and reading of data to and from the storage area; and a buffer memory that temporarily stores data to be written in the storage area, in which the controller selects one compression method from a first reversible compression method and a second reversible compression method based on access performance to the flash memory, and determines to compress data based on the selected one compression method and to write the compressed data to the storage area, and the first reversible compression method has a lower compression ratio and a slower compression speed than the second reversible compression method.

Abstract: When a logical capacity of a nonvolatile semiconductor memory is increased, after a logical capacity which is allocated to a RAID group but unused is released, the RAID group is reconfigured to include the released logical capacity and the increased logical capacity. When the logical capacity of the nonvolatile semiconductor memory is reduced, after the reduced logical capacity is released from the RAID group, the RAID group is reconfigured with the released logical capacity.

Abstract: A system including a first storage drive and a superior device superior to the first storage drive, wherein the superior device specifies a first allowable environmental temperature that makes the remaining lifetime of the first storage drive longer than the remaining operation schedule period of the first storage drive, and controls an environmental temperature adjusting device that adjusts the environmental temperature of the first storage drive on the basis of the first allowable environmental temperature.

Abstract: A storage subsystem constituting a pool using storage media having rewrite life and providing a logical volume having a virtual capacity to a host, wherein the storage subsystem monitors whether shortage of a remaining rewrite life of the capacity pool will occur or not within an operation period of the storage subsystem, and when it is determined that shortage of the remaining rewrite life will occur, the subsystem converts the rewrite life required to cover the shortage into drive capacity and indicates the same, or indicates the same by reducing an existing pool capacity, and requests maintenance of the subsystem. A maintenance method is provided, wherein elongation of life is executed by adding a capacity to the pool at the time of indication, and as for addition of capacity other than the elongation of life described above, a maintenance fee is charged.

Abstract: It is possible to prevent unoccupied blocks from being depleted by a write of logical-physical management information. A processor is capable of performing an unoccupied user block generation process by moving user data stored in allocated user blocks in order to generate unoccupied user blocks serving as unoccupied blocks among allocated user blocks, and performing an unoccupied meta block generation process by moving meta data stored in allocated meta blocks in order to generate unoccupied meta blocks serving as unoccupied blocks among the allocated meta blocks. The processor calculates the number of unoccupied meta blocks to be consumed, that is, the number of unoccupied meta blocks to be consumed by the unoccupied user block generation process. The processor performs the unoccupied meta block generation process based on the number of unoccupied meta blocks to be consumed.

Abstract: The present invention improves an access performance in an SSD device in which a nonvolatile semiconductor, such as a NAND flash memory, is mounted, or in a storage subsystem having the SSD device built therein, and achieves longer operating life. For this purpose, a plurality of units (logical-physical sizes) for associating a logical address with a physical address is provided in the SSD device or the storage subsystem, and an appropriate logical-physical size is selected in accordance with an I/O size or I/O pattern accessed from a superior device.

Abstract: The present invention improves an access performance in an SSD device in which a nonvolatile semiconductor, such as a NAND flash memory, is mounted, or in a storage subsystem having the SSD device built therein, and achieves longer operating life. For this purpose, a plurality of units (logical-physical sizes) for associating a logical address with a physical address is provided in the SSD device or the storage subsystem, and an appropriate logical-physical size is selected in accordance with an I/O size or I/O pattern accessed from a superior device.

Abstract: A storage subsystem constituting a pool using storage media having rewrite life and providing a logical volume having a virtual capacity to a host, wherein the storage subsystem monitors whether shortage of a remaining rewrite life of the capacity pool will occur or not within an operation period of the storage subsystem, and when it is determined that shortage of the remaining rewrite life will occur, the subsystem converts the rewrite life required to cover the shortage into drive capacity and indicates the same, or indicates the same by reducing an existing pool capacity, and requests maintenance of the subsystem. A maintenance method is provided, wherein elongation of life is executed by adding a capacity to the pool at the time of indication, and as for addition of capacity other than the elongation of life described above, a maintenance fee is charged.