Abstract: A memory stores plural pieces of information on a storage device including a first storage medium and a second storage medium. A processor obtains ratios of accesses to the respective storage mediums to a total number of accesses for the respective storage devices. The processor obtains a first number of requests that is a number of accesses capable of being processed in the respective storage devices within a prescribed time period. An interface preferentially reports information on the storage device having a relatively small difference between the first number of requests and the second number of requests.

Abstract: A program directs a computer to perform processes of acquiring information about a configuration of each storage device group which have a different response efficiency to a request, and information about a maximum response time to the request of each storage device group, calculating a maximum request issuance frequency as a request issuance frequency per unit time as the maximum response time when a response time is checked for each storage device group, calculating an cumulative value of a number of issuance of requests to each storage device group from a Zipf distribution when the request issuance frequency to a unit capacity in storage device groups and a probability of the request issuance frequency are in accordance with the Zipf distribution, and generating an evaluation reference value about the storage device group using the maximum request issuance frequency and the cumulative value of the number of issuances of the request.

Abstract: A characteristic amount for a data redundancy method of a storage apparatus, a characteristic amount for performance of a storage device, a phase change multiplicity, which is a multiplicity at a boundary between a low load and a high load, and the number of read requests per unit time are calculated by using redundancy method information of the storage apparatus, the number of storage devices of the storage apparatus, a used ratio of a used storage area, a ratio of read requests to requests, an average data amount of data read in response to a read request, the number of requests per unit time, and a constant decided based on a processing time for a write request in the storage apparatus and a type of a storage device, and a predicted value of an average response time to a read request is calculated by using the calculated values.

Abstract: A non-transitory computer-readable recording medium stores therein a charge calculating program that causes a computer that manages a database of different data items to execute recording for each data item, information indicating the number of clients that receive the data item; extracting from the information recorded at the recording and for each data item to be received by a given client, information indicating the number of clients receiving the data item; calculating charges for the given client, based on the extracted information; and outputting the calculated charges.

Abstract: An information processing device is provided that provides service by executing a service provider program in a cluster system. The device includes a program information transmission unit that transmits to a monitoring node that monitors the cluster system, a node list information reception unit that receives node list information, an update target selection unit that determines which of the other information processing devices which are not yet updated with the service provider program by referring to the program information in the node list information, a command timing determination unit that determines a time after a lapse of the standby time found in the first update timing information as a command timing of the update command, an update timing information generation unit that generates second update timing information and an update command transmission unit that transmits the update command about the service provider program and the second update timing information.

Abstract: In a computer for executing processing based on a storage management program, a management information storing unit designates, from the data blocks having the same content, main-data used as an access destination and sub-data used as a backup, and stores management information that registers storage nodes as allocation destinations of the respective main-data and sub-data; a load information collecting unit continuously collects load information on the storage nodes; a replacement object detecting unit detects a pair of the main-data and the sub-data having the same content and having a predetermined condition such that a load difference between the allocation destination of the main-data and that of the sub-data exceeds a predetermined allowable value; and a management information updating unit replaces roles of the main-data and the sub-data between the detected pair of data blocks.

Abstract: In a distributed storage system, client terminals make access to virtual storage areas provided as logical segments of a storage volume. Those logical segments are associated with physical segments that serve as real data storage areas. A management data storage unit stores management data describing the association between such logical segments and physical segments. Upon receipt of access requests directed to a specific access range, a segment identification unit consults the management data to identify logical segments in the specified access range and their associated physical segments. A remapping unit subdivides the identified logical segments and physical segments into logical sub-segments and physical sub-segments, respectively, and remaps the logical sub-segments to the physical sub-segments according to a predetermined remapping algorithm. A data access unit executes the access requests based on the remapped logical sub-segments and physical sub-segments.

Abstract: A computer in a disk node executes a data management program. A deduplication-eligible data unit detection module detects a data unit whose deduplication grace period after last write time has expired. A deduplication address fetch module interacts with an index server to obtain a deduplication address associated with a unique value of data stored in a constituent storage space allocated to the data unit that is found to be deduplication-eligible. A constituent storage space deallocation module stores the obtained deduplication address in a data unit record memory, together with information indicating the detected data unit. Simultaneously a constituent storage space deallocation module releases the allocated constituent storage space from the detected data unit.

Abstract: A computer-readable medium storing a data management program makes a computer manage data redundantly stored in storage devices having storage areas split into slices for data management. The data management program realizes the following functions in the computer. A first function receives irregularity information indicating that each of one or more of the storage devices may be possibly faulty, and stores the irregularity information in a storage; and a second function determines, by reference to the irregularity information, whether or not a first storage device containing a slice to be accessed is possibly faulty, on receipt of access information indicating occurrence of a request to access the slice. When yes is determined, the second function instructs an external device to recover data stored in the slice, where the external device controls a second storage device storing redundant data identical to the data stored in the slice.

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: 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: 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 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: 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: 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.

Abstract: A parity-data generating unit generates, in response to a write request containing update data, updated parity data in the parity group to which the update data belongs. A time-series-information generating unit generates time-series information indicating an anteroposterior relationship during writing between the update data and existing data stored in the unit storage area to which the update data is to be written. A time-series-information adding unit adds the time-series information, generated in response to the write request, to the update data as certification time-series information and that adds comparison time-series information to the updated parity data in association with the update data, the comparison time-series information having the same value as the certification time-series information.

Abstract: An allocation control apparatus allocates duplicate logical volume divided areas to virtual storage areas that do not have data storage area in the physical storage area. The apparatus associates identification information of the allocated virtual storage areas, of the duplicate logical volume divided areas, and of duplication source logical volume divided areas to be set in the management information. The apparatus detects, upon a data writing request, based on the management information, the unallocated real storage area in the logical volume divided area. The apparatus reallocates the real storage area to the duplicate logical volume divided area to update the management information. The apparatus identifies, based on the management information, the real storage area allocated to the duplication source logical volume divided area corresponding to the duplicate logical volume divided area. The apparatus copies data stored in the real storage area to the real storage area.

Abstract: A computer-readable recording medium storing a data storage program, a method and a computer are provided. The computer includes a cache table including an address area for storing an address and a user data area for storing user data corresponding to the address, and executes an operation including, reading user data at a specified address from a recording medium, delta-decoding the read difference data, and determining the decompressed user data to be the read user data, and writing the read user data in the user data area of the cache table when a size of the user data read by the delta-decoding is equal to or less than a threshold value and writing an address corresponding to the read user data in the address area of the cache table, obtaining difference data between the user data requested to be written and the corresponding user data and writing the difference data.