Abstract: A storage system according to one aspect of the present invention includes a plurality of storage devices using flash memory as a storage medium. The flash memory used for the storage device may include flash memory configured to operate each cell as a cell capable of storing n-bit information or a cell capable of storing m-bit information (where n<m), where n=2 and m=3. The storage system may periodically acquire a number of remaining erasures from the storage device and predict the lifetime of the storage device by using the acquired number of remaining erasures and the storage device operation time. If the predicted lifetime is greater than a predetermined value (service life), a predetermined number of cells may be changed to cells capable of storing m-bit information.

Abstract: A flash memory controller is configured to hold a read pattern defining an order of selection of read options specifying a parameter value for a read from the flash memory chip. The flash memory controller is configured to execute error correction on data read from the flash memory chip in accordance with the read command. The flash memory controller is configured to designate a next read option specified in the read pattern to read the data from the flash memory chip in a case where all errors in the read data are not corrected by the error correction.

Abstract: A failure region is specified when a failure occurs in a non-volatile semiconductor memory. When a device controller reads data stored in a specific page in a plurality of non-volatile semiconductor memories to detect an uncorrectable error (UE) of the data stored in the specific page, the device controller executes a diagnosis process including specifying a specific storage circuit that is a storage circuit including the specific page, reading data stored in a part of blocks of the specific storage circuit, and specifying, on the basis of a result of reading data stored in the block, a failure region in the specific storage circuit.

Abstract: A nonvolatile memory device includes: a nonvolatile memory including a plurality of physical blocks; and a memory controller configured to execute an internal process of migrating data between physical blocks. The memory controller is configured to select, based on an update frequency level which is identified with respect to a logical address range from a higher-level apparatus, a physical block to be allocated to the logical address range from among the plurality of physical blocks. The memory controller is configured to determine, in the internal process, whether to set a migration destination level (an update frequency level of a migration destination physical block) to a same level as or a different level from a migration source level (an update frequency level of a migration source physical block) based on whether or not an attribute of the migration source physical block satisfies a prescribed condition.

Abstract: A storage system includes a plurality of storage devices, each including a storage medium and a compression function for data, and a storage controller coupled to the plurality of storage devices. The storage controller includes compression necessity information indicating necessity of compression of the data in a write command to be transmitted to a storage device at a write destination among the plurality of storage devices. The storage device at the write destination writes, when the compression necessity information included in the received write command indicates that compression is unnecessary, the data in the storage medium without compressing the data.

Abstract: Provided is a storage system including: a storage medium including a plurality of physical storage areas having an upper limit number of rewrites, and a medium controller that controls I/O (input/output) of data to/from the plurality of physical storage areas; and a storage controller connected to the storage medium, wherein when any of the physical storage areas is not allocated to a write destination logical storage area among a plurality of logical storage areas, the medium controller allocates a vacant physical storage area among the plurality of physical storage areas to the write destination logical storage area and writes write target data to the allocated vacant physical storage area, and the plurality of logical storage areas includes an available logical area group determined based on a relationship between an available capacity of a logical storage capacity and a rewrite frequency of the plurality of physical storage areas.

Abstract: A data management apparatus of a computer system comprises, as a retention rule for volume data, change-time identification information for identifying a point-in-time for changing a logical unit, and migration-destination unit specification information for specifying a migration-destination logical unit. An edge storage apparatus stores first identification information, which enables the identification of volume data in a logical unit, and second identification information, which enables the identification of a logical unit in a storage system after associating the first identification information and the second identification information with each other. A data management apparatus (A1) transfers the volume data from a migration-source logical unit to the migration-destination logical unit conforming to the migration-destination unit specification information subsequent to a point-in-time identified in accordance with the change-time identification information.

Abstract: Availability of an information system including a storage apparatus and a host computer is improved. A host system includes a first storage apparatus provided with a first volume for storing data, and a second storage apparatus for storing the data sent from the first storage apparatus. In case of a failure occurring in the first storage apparatus, the host sends the data to be sent to the first storage apparatus to the second storage apparatus.

Abstract: Availability of an information system including a storage apparatus and a host computer is improved. A host system includes a first storage apparatus provided with a first volume for storing data, and a second storage apparatus for storing the data sent from the first storage apparatus. In case of a failure occurring in the first storage apparatus, the host sends the data to be sent to the first storage apparatus to the second storage apparatus. The same identification number is used by the host computer for accessing data stored in the first volume via a first virtual volume and for accessing data stored in a second volume of the second storage system via a second virtual volume.

Abstract: Efficient data processing is implemented by using the functions of an external storage apparatus which is connected to the virtual storage apparatus. A storage apparatus which is connected to a host apparatus which requests data I/Os and to an external storage apparatus comprising a storage device respectively via a network, comprising a storage device storing data which is read and written by the host apparatus; and a control device which controls data writing to a storage area, wherein the control device provides a predetermined storage area of the storage device of the external storage apparatus to the host apparatus as one or more virtual volumes, and manages the virtual volumes and function information indicating the functions of the external storage apparatus in association with one another.

Abstract: A storage system including: a controller; and, a plurality of physical storage devices coupled to the controller and constituting a RAID group; wherein the controller provides one or more logical volumes belonging to the RAID group, each of the one or more logical volumes having a plurality of storage areas; and one or more virtual volumes, wherein, when receiving a write request to a virtual volume of the one or more virtual volumes, the controller is configured to: allocate a storage area in a logical volume to the virtual volume, as an allocated storage area, where reliability of the storage area is used as a criterion in a selection of the storage area for allocation to the virtual volume; and write data to the allocated storage area, wherein, the controller is configured to selectively perform a RAID allocation process to a storage area allocated to a virtual volume.

Abstract: A computer system includes: a first storage apparatus; a second storage apparatus; a first volume of the first storage apparatus; and a second volume of the second storage apparatus; wherein the first volume and the second volume have a copy pair relationship and a host system recognizes the second volume as the same volume as the first volume; and wherein the first storage apparatus sends reservation information of the first volume to the second storage apparatus; and the second storage apparatus controls access from the host system on the basis of the received reservation information.

Abstract: A data management apparatus of a computer system comprises, as a retention rule for volume data, change-time identification information for identifying a point-in-time for changing a logical unit, and migration-destination unit specification information for specifying a migration-destination logical unit. An edge storage apparatus stores first identification information, which enables the identification of volume data in a logical unit, and second identification information, which enables the identification of a logical unit in a storage system after associating the first identification information and the second identification information with each other. A data management apparatus (A1) transfers the volume data from a migration-source logical unit to the migration-destination logical unit conforming to the migration-destination unit specification information subsequent to a point-in-time identified in accordance with the change-time identification information.

Abstract: Information system, including: first and second storage apparatuses connected to a host computer and including volumes designated by a common volume identifier, but being accessible via differing paths of differing priorities. A failure detection storage apparatus connected to the storage apparatuses includes a third volume. Any I/O request designating the common volume identifier, is first sent to the first volume though the first access path, but upon error is then sent to the second volume thorough the second access path. The first or second storage apparatus detecting failure stores, in the third volume, a failure information flag. Upon receiving an I/O request through the second access path, the second storage apparatus determines whether the failure information flag is stored in the third volume, and sends an error reply of the I/O request to the host computer if the failure information flag is stored in the third volume.

Abstract: Availability of an information system including a storage apparatus and a host computer is improved. A host system includes a first storage apparatus provided with a first volume for storing data, and a second storage apparatus for storing the data sent from the first storage apparatus. In case of a failure occurring in the first storage apparatus, the host sends the data to be sent to the first storage apparatus to the second storage apparatus.

Abstract: There is disclosed a data storage system used in a computer environment where there are plural host computers and plural storage array controllers. When a remote copy is made while assuring the order of writing across plural storage array controllers, one of the host computers gains copy information about all the storage array controllers associated with the remote copy as a representative. The representative one of the storage array controllers collects and stores copy statuses which are individually managed by the storage array controllers for which a remote copy is made. The host computer gains the copy statuses from the representative controller using an instruction to gain the copy statuses.

Abstract: A storage system including: a controller; and, a plurality of physical storage devices coupled to the controller and constituting a RAID group; wherein the controller provides one or more logical volumes belonging to the RAID group, each of the one or more logical volumes having a plurality of storage areas; one or more virtual volumes, wherein, when receiving a write request to a virtual volume of the one or more virtual volumes, the controller allocates a storage area in a logical volume to the virtual volume; and writes data to the allocated storage area, wherein, when a physical storage device of the plurality of physical storage devices fails, the controller selectively performs a RAID restore process to a storage area allocated to a virtual volume.

Abstract: A computer system includes: a first storage apparatus; a second storage apparatus; a first volume of the first storage apparatus; and a second volume of the second storage apparatus; wherein the first volume and the second volume have a copy pair relationship and a host system recognizes the second volume as the same volume as the first volume; and wherein the first storage apparatus sends reservation information of the first volume to the second storage apparatus; and the second storage apparatus controls access from the host system on the basis of the received reservation information.

Abstract: Even when a host does not give a write time to write data, consistency can be kept among data stored in secondary storage systems. The present system has plural primary storage systems each having a source volume and plural secondary storage systems each having a target volume. Once data is received from a host, each of the plural storage systems creates write-data management information having sequential numbers and reference information and sends, to one of the primary storage systems, the data, sequential number and reference information. Each of the secondary storage systems records reference information corresponding to the larges sequential number among serial sequential numbers and stores, in a target volume in an order of sequential numbers, data corresponding to reference information having a value smaller than the reference information based on the smallest value reference information among reference information recorded in each of the plural secondary storage systems.

Abstract: Availability of an information system including a storage apparatus and a computer is improved. First and second storage apparatuses execute remote copy of copying data written into a first primary volume from the computer to a second primary volume, at least one of the first and second storage apparatuses executes local copy of copying the data written into the first or second primary volume in a self-storage apparatus to the corresponding first or second secondary volume, and the computer switches the destination of a write request of the data from the first storage apparatus to the second storage apparatus in case of a failure occurring in the first storage apparatus.