Abstract: The client computer which transmits an access request specifying an object existing in the first file system and the second computer which accesses the second file system are connected to the first computer which accesses the first file system. The second file system includes a shared directory. A specific object which is an object complying with the path name including the name determined in accordance with the type of the second computer is stored in the shared directory. The controller mounts the shared directory to the first file system. The controller creates a link which comprises a name determined in accordance with a certain naming regulation independent of the type of the computer and corresponds to the specific object in the first file system.

Abstract: Difference information between two snapshots from a first point-in-time snapshot, which has been copied, to an N.sup.th point-in-time snapshot, which constitutes the latest point-in-time snapshot, is acquired to a memory module. The memory module stores two or more pieces of difference information. The two or more pieces of difference information comprise difference information that shows the difference between a first point-in-time snapshot and any snapshot other than the first point-in-time snapshot of N snapshots. Copy difference information, which is information that shows the difference between the first point-in-time snapshot and a specified snapshot from among N snapshots, and which is used in copying the specified snapshot, is created on the basis of the two or more pieces of difference information.

Abstract: According to the prior art virtual file backup method, backup is performed without saving a file configuration information, so that the backup file cannot be restored as a virtual file during restoration, and the usage capacity of the disk is increased. According to the present invention, an actual data managed by a virtual file, an actual data managed by one or more element files and a configuration information of the virtual file are respectively stored during backup, wherein during restoration, the virtual file is restored based on the configuration information of the virtual file.

Abstract: The present invention provides a computer system capable of providing the latest statistics on a file system in real time. The computer system includes a memory having a program for executing statistics on a file system, and a controller for executing the program. When the file system is accessed, the controller compares first statistic information before access processing on the file system with second statistic information after the access processing; and if it is determined that any difference exists between the first statistic information and the second statistic information, the controller updates the statistic result of the file system based on the difference.

Abstract: A control unit of a storage system controller receives an access command to a first file specifying a first access position in the first file. A storage apparatus stores management information of the first file and management information of each of subfiles obtained by dividing the first file. The management information of the first file contains information associating a data position in the first file and management information of a subfile containning data at the data position. The management information of each of the subfiles contains information associating a data position in the corresponding subfile and a physical storage position. The control unit references the management information of the first file to identify the management information of the subfile containning the data at the first access position, and references the management information of the identified subfile to identify a physical storage position of the first access position.

Abstract: The prior art information system could not migrate a file in a file sharing system provided by a file storage to a plurality of cloud storages having different forms of connection and different properties, and therefore, could not manage the files via a single Stub information. The present invention provides a data mover program in a file storage to select one or more migration destination cloud storages based on a migration policy, a connection information table of cloud storages and a property information table of cloud storages. Then, a Stub information of the migrated file is created, and an identification information of the file in the cloud storage is stored in a file information table. When access occurs from a client to a file storage, the data mover program downloads a file from the cloud storage stored in the file information table corresponding to the Stub information and provides the file to the client.

Abstract: The system of the present invention curbs an unnecessary inter-tier file migration and provides an inter-tier file migration that conforms to the utilization state. The hierarchical storage management system respectively migrates a frequently accessed file to the upper Tier, and an infrequently accessed file to the lower Tier. This system carries out inter-tier file migration in conformance with the utilization state. This system provides functions for anchoring a Tier for storage for a specified file, and for not permitting an inter-tier file migration.

Abstract: An application processing system including a database server and a storage device which is connected with a standby application processing system including a secondary database server and a secondary storage device to continue to carry out application processing in the case of a fault, disaster, etc. or for maintenance. The storage device of the application processing system issues a log disk update request to the secondary database server of the standby system to update a log disk of the standby system and thereby create a duplicate of the log disk for the DBMS of the application processing system. This allows the DBMS of the standby system to roll forward the log data in the duplicated log to update duplicated data on the secondary storage device.

Abstract: In acquiring a snapshot, when data in a P-VOL is updated, it is determined whether the same data as target data to be stored in a certain second storage area specified by a certain second address of a D-VOL is already stored in a different second storage area specified by a different second address of the D-VOL, the target data being the differential data generated by the update. When the same data as the target data is stored, the target data is not newly stored in the D-VOL, and the different second address, specifying the different second storage area where the same data is stored, is registered in a snapshot management table (CoW table), in association with a certain first address specifying a certain first storage area where the data from which the target data has been generated is stored.

Abstract: Difference information between two snapshots from a first point-in-time snapshot, which has been copied, to an N.sup.th point-in-time snapshot, which constitutes the latest point-in-time snapshot, is acquired to a memory module. The memory module stores two or more pieces of difference information. The two or more pieces of difference information comprise difference information that shows the difference between a first point-in-time snapshot and any snapshot other than the first point-in-time snapshot of N snapshots. Copy difference information, which is information that shows the difference between the first point-in-time snapshot and a specified snapshot from among N snapshots, and which is used in copying the specified snapshot, is created on the basis of the two or more pieces of difference information.

Abstract: The client computer which transmits an access request specifying an object existing in the first file system and the second computer which accesses the second file system are connected to the first computer which accesses the first file system. The second file system includes a shared directory. A specific object which is an object complying with the path name including the name determined in accordance with the type of the second computer is stored in the shared directory. The controller mounts the shared directory to the first file system. The controller creates a link which comprises a name determined in accordance with a certain naming regulation independent of the type of the computer and corresponds to the specific object in the first file system.

Abstract: When performing migration of data from a migration source file server which is not endowed with any HSM interface, to a migration destination file server which is endowed with HSM, a volume of high capacity is needed for the migration destination file server, and moreover the performance deteriorates directly after the migration. However, with this system, the manager is enabled to set a migration policy using attribute information which can be acquired through a standard file access interface possessed by a file server program, and, when setting the attribute information of the migration destination file, the tier of the file which is to be created is determined, and the migration destination file is created, on the basis of this attribute information and migration policy.

Abstract: In a computer system according to an embodiment of the present invention, a first slave server includes copy management information associating a master file system identifier with an identifier of a slave server including a copy of the master file system identified by the master file system identifier. The first slave server acquires a copy of a part of a master file system. The copy includes a stub-state object (file or directory). The first slave server searches the copy management information for a slave server to be queried regarding information for materializing the stub-state object. If the slave server to be queried includes the information for materialization, the first slave server materializes the stub-state object using the information for materialization acquired from the queried slave server.

Abstract: The file synchronization processing among sites which can reduce the response time is realized. By the CAS device creating a list of at least a part of the file groups which the first sub-computer system archived or backed up to the data center as an update list and transferring the update list to the second sub-computer system, the second sub-computer system determines whether the file is valid or not by using the update list (See FIG. 2).

Abstract: In order to provide HSM that can effectively use the storage capacity of an upper Tier in an HSM system, a lower Tier of the HSM system detects a group of files having the same data content from a plurality of files stored in the lower Tier, and keeps at least one of the real data of the group of files having the same data content while deleting the rest of the data. The upper Tier receives the process result from the lower Tier. Then, in response to a read request from the host computer that specifies a file included in the group of files and transferred to the upper Tier from the lower Tier, the upper Tier identifies the at least one of the data that is kept and corresponding to the specified file, and responds to the host computer.

Abstract: Difference information between two snapshots from a first point-in-time snapshot, which has been copied, to an Nth point-in-time snapshot, which constitutes the latest point-in-time snapshot, is acquired to a memory module. The memory module stores two or more pieces of difference information. The two or more pieces of difference information comprise difference information that shows the difference between a first point-in-time snapshot and any snapshot other than the first point-in-time snapshot of N snapshots. Copy difference information, which is information that shows the difference between the first point-in-time snapshot and a specified snapshot from among N snapshots, and which is used in copying the specified snapshot, is created on the basis of the two or more pieces of difference information.

Abstract: In order to provide HSM that can effectively use the storage capacity of an upper Tier in an HSM system, a lower Tier of the HSM system detects a group of files having the same data content from a plurality of files stored in the lower Tier, and keeps at least one of the real data of the group of files having the same data content while deleting the rest of the data. The upper Tier receives the process result from the lower Tier. Then, in response to a read request from the host computer that specifies a file included in the group of files and transferred to the upper Tier from the lower Tier, the upper Tier identifies the at least one of the data that is kept and corresponding to the specified file, and responds to the host computer.

Abstract: A proposal is made of a file management system and method capable of reliably deleting unnecessary data. In a file management console and method for reading or writing data of a file from or in a first volume, which is provided by a storage device, in response to a request sent from a host computer, one snapshot or multiple snapshots that relate to the first volume and can be updated are created. In response to an externally issued designated file deletion command, a designated file is deleted from all of the first volume and snapshots or part thereof specified in the deletion command. At this time, the data items of the designated file in the first volume and/or snapshots from which the designated file should be deleted are overwritten with invalid data. Moreover, pieces of management information on the designated file are changed to a reference-disabled state.

Abstract: A storage system for optimizing volume capacity among file management computers of sharing a storage apparatus is provided. A capacity management computer acquires statistical information such as access history information from the file management computers and the storage apparatus. The capacity management computer executes a capacity optimizing process for the storage apparatus in association with a specified date. The capacity management computer calculates optimized capacity for the respective file systems based on the statistical information by redistributing available capacity of volumes according to a predetermined standard such as a capacity consuming speed. Further, the capacity management computer instructs the file management computers and the storage apparatus to optimize a size of the file systems and the capacity of the volumes, respectively.

Abstract: Time required for a file server to determine files to be migrated from a first storage region to a second storage region is reduced. A file service system coupled to the storage system for providing a first storage region and a second storage region stores identifiers of files that have been accessed by a client, in accessed file identifier information and determines the files to be migrated from the first storage region to the second storage region based on metadata of the files stored in the first storage region and the accessed file identifier information.