Abstract: There is provided a storage control device that is communicably connected to a plurality of storage devices and a plurality of spare storage devices through a plurality of paths. The storage control device includes: a memory configured to store path information associating the plurality of spare storage devices and the plurality of paths with each other; and a selection unit configured to select a spare storage device that is a replacing apparatus from among the plurality of spare storage devices based on a path connection condition determined in accordance with a path in which the storage device that is a replacement target among the plurality of storage devices is connected and the path information.

Abstract: Write commands for a storage device specify write data with either a first data step size or a second data step size. In the former case, the storage device performs a read-modify-write (RMW) cycle which includes reading data with the second data step size. In the latter case, the storage device executes the command in a single write cycle. A command sorting unit sorts received commands into two groups, first commands and second commands, when storing them in a memory. First commands are write commands whose data boundaries do not match with the second data step size. Second commands include write commands whose data boundaries match with the second data step size. A command issuing unit converts first commands into a second command upon predetermined conditions. The command issuing unit issues the second commands to the storage device, in preference to the first commands.

Abstract: A storage device which includes a plurality of magnetic disk drives has a storage unit that stores, for each of the plurality of magnetic disk drives, information of whether or not the magnetic disk drive is incorporated in a redundant structure, a specifying unit that specifies, among the plurality of magnetic disk drives, a plurality of magnetic disk drives which have a redundant structure on the basis of the information stored in the storage unit, and a control unit that controls, for the plurality of magnetic disk drives specified by the specifying unit, an execution timing of sweep operation in which a head smoothes a lubricant material such that the sweep operation is executed for a single magnetic disk drive at a time.

Abstract: A control device including a processor. The processor configured to allocate a data area of a memory device to a plurality of memory areas of data blocks of a first size; allocate identical data blocks of the first size to a plurality of the data areas of the memory device; manage management information indicating a data storing state of the plurality of memory areas of data blocks of the first size in each data area; determine, based on the management information regarding a plurality of data areas allocated with respect to a data block to be written, one data area from the plurality of data areas; and generate write data of a second size, which is different from the first size, including data of the data block to be written and write the write data in the one data area.

Abstract: A storage device which includes a plurality of magnetic disk drives has a storage unit that stores, for each of the plurality of magnetic disk drives, information of whether or not the magnetic disk drive is incorporated in a redundant structure, a specifying unit that specifies, among the plurality of magnetic disk drives, a plurality of magnetic disk drives which have a redundant structure on the basis of the information stored in the storage unit, and a control unit that controls, for the plurality of magnetic disk drives specified by the specifying unit, an execution timing of sweep operation in which a head smoothes a lubricant material such that the sweep operation is executed for a single magnetic disk drive at a time.

Abstract: A storage apparatus including: a first controller that generates an access to a storage device; the first controller includes: a first relay unit configured to relay the access to the storage device; and an access control unit configured to be activated after activation of the first relay unit and to relay the access to the storage device via a second relay unit; and a second controller that includes the second relay unit and generates the access to the storage device, wherein when the first relay unit receives a connection request for an access path between the first relay unit and the storage device from the second controller, the first relay unit establishes the access path to the storage device irrespective of an activation state of the access control unit.

Abstract: A storage control device obtains an access request having a random characteristic or an access request having a sequential characteristic, compares a threshold with a ratio of the number of commands corresponding to the access request having the random characteristic to the number of commands corresponding to the access request having the sequential characteristic, generates and issues a command to which first identification information for instructing a storage to determine an execution order of commands issued to the storage has been assigned or a command to which second identification information for instructing the storage to execute commands in an order in which the storage received the commands has been assigned, in accordance with a result of the comparison, measures a time from issuance of the command to a response from the storage when the obtained access request has a random characteristic, and adjusts the threshold.

Abstract: A control apparatus includes a memory and a processor. The processor sets a comparison reference value on the basis of a first response time of a response to a first command that has been issued to a transmission destination. The processor stores the comparison reference value in the memory. The processor compares, when a second command is to be issued, a differential amount of data flows with the comparison reference value stored in the memory. The differential amount indicates a difference between an amount of data flows related to commands that have been issued to the transmission destination and an amount of data flows related to response data that have been received from the transmission destination. The processor restrains, when the differential amount exceeds the comparison reference value, the second command from being issued.

Abstract: A RAID apparatus includes a plurality of recording devices, a first adaptor connected to a first interface which is connected to a high-level apparatus, a controller for controlling processing of data transmitted by the high-level apparatus, and a second adaptor that connects to a second interface connected to a plurality of recording devices. The controller has a first memory area in which said data are stored, a second memory area used for a write-back of the data in said plurality of recording devices, a write-back information control unit controlling a write-back type of data stored in the first memory area and a usage state of the second memory area, a write-back data determination unit for determination of data to be written-back based on the write-back information, and a write-back execution unit for executing a write-back of the data to be written back on the plurality of recording devices.

Abstract: A storage apparatus including: a first controller that generates an access to a storage device; the first controller includes: a first relay unit configured to relay the access to the storage device; and an access control unit configured to be activated after activation of the first relay unit and to relay the access to the storage device via a second relay unit; and a second controller that includes the second relay unit and generates the access to the storage device, wherein when the first relay unit receives a connection request for an access path between the first relay unit and the storage device from the second controller, the first relay unit establishes the access path to the storage device irrespective of an activation state of the access control unit.

Abstract: A control method includes the steps of storing data in a cache; generating parity data corresponding to the data stored in the cache and storing the parity data in a buffer; writing the data stored in the cache and the parity data stored in the buffer into a plurality of the storage units; reading the data and the parity data from the plurality of storage units; checking error over the read out data by using the read out parity data; storing, if an error is detected in the read out data and the read out parity data, data for reading a plurality of data constituting a stripe in each of the plurality of storage units in the buffer, regenerating parity data by using the plurality of data readout from the storage units; and overwriting the plurality of data and the parity data into the plurality of the storage units.

Abstract: In a RAID apparatus, an error determining processing unit determines whether an HDD is normal based on an error determining condition obtained from an amount of increase of NON MEDIUM ERROR COUNT and the number of accesses memorized on a control table, and detects the HDD with abnormal performance.

Abstract: According to an aspect of an embodiment, a method for controlling a controller connected to a plurality of storage units storing data, the controller including a cache and a buffer, the method comprising the steps of: storing data in the cache; generating parity data corresponding to the data and storing the parity data in the buffer; writing the data and the parity data into the plurality of the storage units; comparing the parity data stored in the buffer with the parity data written into and read out from at least one of the storage unit; deleting, when the parity data stored in the buffer is different from the parity data read out from the storage unit, the parity data from the buffer; and regenerating parity data from data stored in the cache and rewriting the regenerated parity data into at least one of the storage unit.

Abstract: According to an aspect of an embodiment, a method for controlling a controller connected to a plurality of storage units which are arranged in a redundant configuration, the controller reading data stored in the plurality of storage units in accordance with requests received from a host computer, the method comprising the steps of: receiving requests to read data successively from one of the storage units from the host computer; reading a part of requested target data from said one of the storage units; reading associated data and parity data stored in other storage units corresponding to other part of requested target data; generating other part of requested target data on the basis of the associated data and the parity data read out from the other storage units; and transmitting the part of the target data and the other part of the target data to the host computer.

Abstract: A disk management method for managing a disk management device for writing and reading data to and from a disk drive in which a recording medium is managed in a first control unit. The disk management method includes an error checking operation for checking an error on the recording medium in the first control unit, an error correction operation for correcting the error detected in the error, an error correcting operation for correcting the error detected in the error checking operation after converting data including the error to the second control unit, a data loss registration operation for registering a region in which data are lost due to an inconsistency between the first control unit and second control unit in a data loss region table, and a data loss recovery operation for recovering the loss of data with reference to the data loss region table.

Abstract: A device adaptor that controls a disk, wherein a storage area is divided into a plurality of blocks, detects a block that includes a read error. Next, the device adaptor detects a write omission in blocks that are within a predetermined range from the block that includes the read error. To be specific, the device adaptor reads data from the blocks that are in the vicinity of the block that includes the unrecovered read error in a suspect disk. Next, the device adaptor reads from a redundant disk, data of a block that corresponds to the block that includes the unrecovered read error (data of block “B” in an example shown in FIG. 1) and compares the read data to the data read from the suspect disk to detect the write omission.

Abstract: In a system for dispersively storing data and parity in a plurality of storage devices, information in a first storage device is restored by using information stored in the storage devices other than the first storage device when the first storage device fails. And information in a non-restored area in the first storage device and information in a second storage device are restored by using information stored in the storage devices other than the first and the second storage devices when the second storage device fails while the information in the first storage device is being restored.

Abstract: A storage unit includes a cache memory, a cache controller which accesses the cache memory, one or more disk units, a data receiving unit, a merge interpolation determination unit, a data readout unit, a write data generation unit and a data write unit. The data receiving unit receives, from the cache controller, unit readout data that includes update records updated by the cache controller and is unit of data read from the cache memory. The merge interpolation determination unit determines whether the received unit readout data is merge interpolated. The data readout unit reads, from the disk unit, data corresponding to the unit readout data when the unit readout data is determined to be merge interpolated. The write data generation unit generates data to be written to the disk unit by merge interpolating the unit readout data. The data write unit writes, to the disk unit, the generated data.

Abstract: In a disk array system, when a failure occurs in a disk unit under control, a disk controller performs a rebuild process for rebuilding data stored on the faulty disk unit on a spare disk unit (HS). When a rebuild control section accepts an I/O request from a host before completing the rebuild process in all target areas, the rebuild control section specifies a management unit area including a target area of the I/O request and determines whether the rebuild process is completed in the management unit area. If the rebuild process is not completed in the management unit area, the rebuild control section performs the rebuild process in the management unit area by a rebuild process section and rebuilds data on the HS. After that, an I/O request handling section handles the I/O request.

Abstract: A disk array apparatus includes a first converting unit that performs first conversion on storing object data received in a first control unit from a controller to convert the storing object data into data in a second control unit, the controller including a selecting section that selects, on the basis of the access state monitored by a monitoring section, one from the controller and said first converting unit, and a second converting unit that performs, if the controller is selected by the selecting section, a second conversion, different from the first conversion, on the object data to convert the object data managed in the first control unit into the data in the second control unit. With this configuration, the disk array apparatus accomplishes the object to improve the accessibility to different types of storage units that manage data storing in different control units.