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: A computer executes a data allocation control program to control allocation of data in a plurality of disk nodes. A redundancy restoration module executes a redundancy restoration procedure by commanding disk nodes to create a new copy of redundancy-lost data. An error message reception module receives a write error message indicating a write error in a storage device during the redundancy restoration procedure and records an identifier of the faulty storage device in an error record memory. A copy command module identifies accessed data in the faulty storage device and commands a relevant disk node to create a copy of the identified data in the faulty storage device in the case where there is no redundant copy of the data.

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: A non-transitory, computer readable storage medium storing a program for a computer being capable of accessing a group of nodes having divided-data structures obtained by dividing a data structure having a transposed hierarchical bloom filter of a hierarchical bloom filter and sets of data blocks by a predetermined bit width, wherein the hierarchical bloom filter has h-stage bloom filter arrays each having a bit width of “s”, the hth-stage bloom filter array having bits indicating false positives or negatives and the pth-stage bloom filter array having n=d[h-(p-1)] bloom filters (where 1?p?h) each having a bit width of m=s/d[h-(p-1)] (where d indicates a division number for the hth-stage bloom filter array), the transposed hierarchical bloom filter is obtained in the bloom filters in the bloom filter array, and the set of data blocks corresponds to the first-stage bloom filter array of the hierarchical bloom filter.

Abstract: A software update management apparatus includes a migration pattern table generation unit for reading a pre-migration environment table and a post-migration environment table and judging a migration content between before and after the update, for each function of a target disk node, and for reading a migration pattern determination table and determining a migration pattern to be applied to the target disk node based on the migration content and the migration pattern determination table. The software update management apparatus also has an update unit for reading the post-migration environment table, issuing an instruction to the target disk node according to the migration pattern determined by the migration pattern table generation unit, and updating software which executes each function of the target disk node.

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: 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: Nodes respectively store a multilayer transposed Bloom filter. A client selects a node N1 from among the group of nodes and transmits a search request to the node N1. Upon receiving a reply from the node N1, the client determines whether the received search result indicates “positive”. If the search result is not positive, the client selects in order of node number, a node N2 and transmits a search request to the node N2. Upon receiving a reply from the node N2, the client determines whether the received search result indicates “positive”. Upon determining that the search result is positive, the client outputs the search result and ends the search notification process.

Abstract: A non-transitory, computer readable storage medium storing a program for a computer being capable of accessing a group of nodes having divided-data structures obtained by dividing a data structure having a transposed hierarchical bloom filter of a hierarchical bloom filter and sets of data blocks by a predetermined bit width, wherein the hierarchical bloom filter has h-stage bloom filter arrays each having a bit width of “s”, the hth-stage bloom filter array having bits indicating false positives or negatives and the pth-stage bloom filter array having n=d[h-(p-1)] bloom filters (where 1?p?h) each having a bit width of m=s/d[h-(p-1)] (where d indicates a division number for the hth-stage bloom filter array), the transposed hierarchical bloom filter is obtained in the bloom filters in the bloom filter array, and the set of data blocks corresponds to the first-stage bloom filter array of the hierarchical bloom filter.

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 data management device includes a memory including a multistage Bloom Filter, a first stage being divided into filter parts of which the number is same as that of data blocks, and a pth stage being divided into filter parts of which a size is a combination of filter parts of a (p?1)th stage; a registration unit registering an entry of data in a filter part of the first stage corresponding to a data block where the data is stored, and the entry of the data to a filter part of the pth stage corresponding to the filter part of the first stage where the entry of the data is registered; and a search unit determining which filter part of the first stage an entry of data being searched is registered in by narrowing down filter parts from the Bloom Filter of which a stage number is large.