Abstract: An internode put requesting unit detects a time-out with respect to a put request issued to the next node in the order of a multiplexing chain and notifies a put/get executing unit of the time-out. The put/get executing unit sends an error to the previous node in the order of the multiplexing chain or a client and instructs a put-failed-data synchronizing unit to synchronize data failed to be put, and the put-failed-data synchronizing unit performs a synchronization process. A primary makes other put requests wait until completion of the synchronization process. Furthermore, when having received the error, the client issues a get request to the tail end of the multiplexing chain.

Abstract: A storage system having a plurality of storages. The each of the storages include a memory and a processor coupled to the memory. The processor executes a process including transmitting an update request for data which is commonly stored in the plurality of storages according to a predetermined transmission order indicating a path to transfer the update request. The process includes updating data when receiving an update request from another storage. The process includes changing the predetermined transmission order to a transmission order in which one or more storages included in the path are excluded according to the number of times the update request for the data is received.

Abstract: A storage device is one of a plurality of storage devices storing replicas of data. The storage device includes a memory and a processor coupled to the memory. The processor executes a process includes transmitting an update request to at least one destination storage device through a plurality of paths when the storage device is requested to update the data by a client. The process includes notifying the client that the updating of the data has been completed when having received a response through one of the paths, the response being issued by the destination storage device serving as the terminal point of the path when the destination storage device receives the update request through all the paths having the destination storage device as the terminal point.

Abstract: A management device obtains, from the plurality of storage nodes, information of accesses which are made to the actual storage areas included in the storage nodes, generating load information of the actual storage areas based on the access information, and storing the generated load information in a load information storage unit. The device changes, based on the load information stored in the load information storage unit, the assignment relations of the actual storage areas with respect to the virtual storage areas such that loads of the storage nodes are leveled. The device instructs the plurality of storage nodes to move the data in the actual storage areas depending on change in the assignment of the actual storage areas to the virtual storage areas.

Abstract: A computer-readable recording medium stores a program that causes a computer to execute a writing control process that includes receiving a writing request to write a first data to a first storage apparatus; determining a second data from among a series of data and based on a writing sequence of the series of data written to the computer and a count of storage areas at a second storage apparatus that sequentially selects from among the storage areas when data is received, a storage area to be over written by the received data, where the second data is written to the first storage apparatus and is identical to data that is stored in the storage area to be selected next at the second storage apparatus; and transmitting copy data of the first data to the second storage apparatus, when the second data has been written to the first storage apparatus.

Abstract: In a computer executing processes based on a storage management program, an attribute collection unit collects attributes of storage nodes. A group creation unit creates at least two groups that include the storage nodes, in accordance with the attributes of the storage nodes collected by the attribute collection unit. A data allocation unit allocates distributed data and redundant distributed data to the groups created by the group creation unit in such a manner that the distributed data and the redundant distributed data having the same content as the distributed data are placed in different groups.

Abstract: The disclosed method includes obtaining a result concerning a busy rate and the number of accesses per unit time for a storage device including first and second storage areas; determining, from the result, whether an event that a first indicator value for the busy rate is reset occurs; when the event occurred, notifying a controller that makes the number of accesses for the second storage area not greater than the notified number of accesses of the first number of accesses less than the second number of accesses, which was notified immediately before; obtaining another result; updating the first indicator value based on another result; calculating the third number of accesses so that a sum of busy rates corresponding to the third number of accesses and corresponding to the designated number of accesses becomes equal to the updated first indicator value; and notifying the controller of the third number of accesses.

Abstract: Processing time required from transmission of a request packet including a processing request from a client, until return of a reply packet in which internal information including an operation status of a plurality of servers is added to an execution result of processing corresponding to the processing request, obtained by the servers in cooperation with each other, is calculated by a function incorporated beforehand in the respective servers. Moreover, the internal information added to the reply packet is extracted and stored in an internal information DB in association with the calculated required time of the processing. Furthermore predetermined statistical processing is performed with respect to the internal information and the required time associated with the internal information stored in the internal information DB to analyze the operation status of the plurality of servers.

Abstract: A data management apparatus sends specific data and key information corresponding to the specific data to another apparatus, when executing a process to change a storage destination of the specific data in which the hash value obtained by applying a predetermined hash function to corresponding key information belongs to a certain range, from the data management apparatus to the other apparatus, and sends the identification information of the other apparatus stored in correspondence with the certain range to a request source of an operation request, when the operation request with respect to data corresponding to key information is received after the process.

Abstract: A recording medium storing a logical volume configuration information distribution program causing a computer to execute processing based on logical volume configuration information that defines a correspondence relation between a virtual storage area in a logical volume defined virtually and a real storage area in a storage unit, the logical volume configuration information distribution program includes: when the correspondence relation between the virtual storage area and the real storage area is changed, referencing an access node list storage unit for storing an access node list in which identification information of the access node is registered, and transmitting update information that indicates an updated correspondence relation concerning the virtual storage area whose correspondence relation with the real storage area has been changed, to the access node indicated in the access node list via the network.

Abstract: Upon receipt of a first key and first data, a control unit exercises control to store second data indicating a second key in association with the first key in a first node and to store the first data in association with the second key in a second node. Upon receipt of an access request that specifies the first key, the control unit detects that data stored in association with the first key is the second data, and accesses the first data stored in the second node on the basis of the second key indicated by the second data.

Abstract: A control unit shifts a boundary between a range of hash values allocated to a first node and a range of hash values allocated to a second node from a first hash value to a second hash value to thereby expand the range of hash values allocated to the first node. The control unit moves data which is part of data stored in the second node and in which hash values calculated from associated keys belong to a range between the first hash value and the second hash value, from the second node to the first node.

Abstract: In a multinode storage system, a virtual disk associated with a storage device to be connected is created, and a slice of a connected storage device is allocated to one segment of the virtual disk. Next, one slice of data in the storage device to be connected is copied to the connected storage device. The rest of the data in the storage device to be connected is divided into slices, which are allocated to segments of the virtual disk. Then, metadata of the rest of the slices is written into a management information area in which copying of the data therefrom has been completed.

Abstract: An information processing apparatus includes a first storage unit and a processor. The first storage unit includes a first storage area. The processor receives a first request to write first data into the first storage area. The processor requests an external apparatus to write the first data into a second storage area in a second storage unit included in the external apparatus. The processor determines whether a first response has been received from the external apparatus. The first response indicates that the first data has been written into the second storage area. The processor writes the first data into the first storage area when the first response has been received. The processor requests, without writing the first data into the first storage area, the external apparatus to write second data stored in the first storage area into the second storage area when the first response has not been received.

Abstract: A lens-interchangeable camera includes a focus detector performing focus detection and a controller performing a drive control of a lens based on a defocus amount. The controller finishes focusing operation without driving the lens when the defocus amount is out a range of a first in-focus determination width, and performs the focusing operation when the defocus amount is out a range of the first in-focus determination width. The controller finishes the focusing operation without performing the focus detection again after completing the drive when the defocus amount is out a range of a second in-focus determination width, and performs the focus detection again after completing the drive when the defocus amount is out a range of the second in-focus determination width. The second in-focus determination width is set to be greater than the first in-focus determination width and be greater than or equal to a drive limit value.

Abstract: An information processing system includes a first processor to store data segments in a first memory, to send the data segments to be stored in the first memory to a second processor, and to read the data segments from the first memory so as to store the data segments in a second memory; and the second processor to store the data segments to be stored sent from the first processor in a third memory, wherein when the first processor notifies the second processor about data that is permitted to be removed, the first processor sends ID information to the second processor that renders a particular data segment that was last stored in the second memory identifiable, and the second processor removes from the third memory the particular data segment and an older data segment stored previous to the particular data segment from the data segments stored in the third memory.

Abstract: An access method includes: obtaining, by a computer, a result of monitoring a busy rate and a number of access operations per unit time of a storage device, the storage device having a first storage area and a second storage area; calculating a characteristic of correlation between the busy rate and the number of access operations per unit time based on the result; calculating a second number of access operations per unit time based on the characteristic of the correlation such that a sum of a first busy rate corresponding to a first number of access operations per unit time and a second busy rate corresponding to a second number of access operations per unit time becomes equal to or lower than a given busy rate; and controlling a number of operations to access the second storage area per unit time based on the second number of access operations.

Abstract: A management apparatus and method that manage a storage system, in which an access node and a storage node, with which the management apparatus is in communication via the network. The management apparatus includes a logical volume judging unit that acquires a plurality of processing requests to each of the plurality of storage areas, references a logical volume allocation information storage unit that stores a correspondence relationship between the plurality of storage areas and the plurality of logical volumes in the storage node, and judges a logical volume corresponding to a storage area to become a processing object of each processing request, and a processing request breakdown calculating unit that counts an acquisition count of each processing request for each logical volume based on a judgment result by the logical volume judgment unit, and calculates a proportion of each acquisition count to a total of respective acquisition counts.

Abstract: In a system management apparatus, a failure detection unit detects a readout failure in one of blocks constituting distributed data stored in a first RAID disk array. A request unit requests a computer to supplement one of the blocks of the distributed data stored in the first RAID disk array in which a readout failure irrecoverable by use of only the data stored in the first RAID disk array occurs, where the computer has a second RAID disk array storing a duplicate of the distributed data stored in the first RAID disk array. And an overwriting unit receives data corresponding to the one of the blocks from the computer, and overwrites the one of the blocks with the received data.

Abstract: A storage management device includes a management unit for managing a storage device assigned thereto and a temporary storage unit assigned thereto. The management unit comprises a backup unit for, when data is written into the storage device, storing the data in the previously assigned temporary storage unit before the writing of the data into the storage device is completed, and a take-over unit for, when data which is already stored in the temporary storage unit, but which is not yet written into the storage device exists when the storage device and the temporary storage unit are assigned, writing the not-yet-written data into the storage device.