Abstract: Each file storage apparatus of a plurality of file storage apparatuses stores a file system, and associates and stores paths of elements in the file system and archive destinations of the elements in an archive storage apparatus. When the file system is operated, each file storage apparatus transmits archive data of an element as an operation target, and operation information including operation details to the archive storage apparatus. The archive storage apparatus receives the archive data and the operation information, stores the archive data, and stores consistency information including the operation information and archive versions indicating a reception order of the operation information.

Abstract: A computer system for sharing objects comprises multiple front-end nodes and a back-end node for providing a namespace shared by the front-end nodes. A first front-end node that is any one of the front-end nodes manages local-lock counts for each of objects managed by the first front-end node. The local-lock count is the number of locks taken by operations to the objects including the directory and sub-objects thereof. Every time receiving a request for processing a target object from a client, the front-end node requests the back-end node to lock a parent directory of the target object if the parent directory has not been locked by the back-end node. The front-end node sends a response of the received request to the client regardless of whether or not the parent directory has been unlocked by the back-end node. If the local-lock count of the parent directory is zero, the first front-end node requests the back-end node to unlock the parent directory.

Abstract: Each file storage apparatus of a plurality of file storage apparatuses stores a file system, and associates and stores paths of elements in the file system and archive destinations of the elements in an archive storage apparatus. When the file system is operated, each file storage apparatus transmits archive data of an element as an operation target, and operation information including operation details to the archive storage apparatus. The archive storage apparatus receives the archive data and the operation information, stores the archive data, and stores consistency information including the operation information and archive versions indicating a reception order of the operation information.

Abstract: A computer system for sharing objects comprises multiple front-end nodes and a back-end node for providing a namespace shared by the front-end nodes. A first front-end node that is any one of the front-end nodes manages local-lock counts for each of objects managed by the first front-end node. The local-lock count is the number of locks taken by operations to the objects including the directory and sub-objects thereof. Every time receiving a request for processing a target object from a client, the front-end node requests the back-end node to lock a parent directory of the target object if the parent directory has not been locked by the back-end node. The front-end node sends a response of the received request to the client regardless of whether or not the parent directory has been unlocked by the back-end node. If the local-lock count of the parent directory is zero, the first front-end node requests the back-end node to unlock the parent directory.

Abstract: The present invention provides a storage subsystem capable of realizing efficient data migration and high access performance. During migration of data between storage subsystems, data migration methods are selected between a “PUSH” type and a “PULL” type method based on a data migration policy set in advance to perform data migration processes. An access characteristics of a file and a folder storing the file are determined based on a file access frequency or a final access date and time information in a migration source storage subsystem, and the migration order of a file group determined to have a high possibility of being accessed during data migration is changed between the “PUSH” type and the “PULL” type.

Abstract: The present invention provides a storage subsystem capable of realizing efficient data migration and high access performance. During migration of data between storage subsystems, data migration methods are selected between a “PUSH” type and a “PULL” type method based on a data migration policy set in advance to perform data migration processes. An access characteristics of a file and a folder storing the file are determined based on a file access frequency or a final access date and time information in a migration source storage subsystem, and the migration order of a file group determined to have a high possibility of being accessed during data migration is changed between the “PUSH” type and the “PULL” type.

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 present invention relates to a migration of a file from a path denotative NAS server to an ID denotative NAS server. In a file management device a migration-use path denotative NAS access section obtains a file deposit location from the path denotative NAS server, selects a migration target file based on the deposit location, and sends a read request with the deposit location of the migration target file to the path denotative NAS server, so as to obtain the migration target file. A migration-use denotative NAS access section generates a write request with the migration target file, sends it to the ID denotative NAS servers, and writes the file therein. In addition, the migration-use ID denotative NAS access section registers a GUID received from the ID denotative NAS servers in a file name/GUID management table, together with the file name of the migration target file.

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: 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: An object of the present invention is to dynamically transfer a virtual file server within a cluster that is configured by a plurality of file servers in which virtual file servers are set up. A storage system includes: a first file server; a second file server; and a disk subsystem, in which: the first file server and the second file server each include a virtual file server control unit that sets up the virtual file server; the virtual file server includes a routing table that stores path information necessary for communication; and the virtual file server started up in the second file server determines a communication path by using the routing table used by the virtual file server in the first file server after taking a failover from the virtual file server of the first file server to the second file server.

Abstract: A storage where one NAS server makes snapshot management information including global paths of snapshots based on snapshot identifiers and global paths of file systems corresponding to the snapshots, so that global paths of both the file systems and snapshots are configured on the same global namespace simultaneously, with a directory configuration of the snapshots being the same in configuration layout as a directory configuration of the file systems; the one NAS server informs other NAS servers of the snapshot management information; memory in each of the NAS servers stores the snapshot management information; the snapshot management information includes the snapshot identifier, local path and global path for each of snapshots obtained by each NAS server at each point in time; and the computer obtains the snapshot management information from at least one of the NAS servers and displays at least a part of the snapshot management information.

Abstract: A file server including: a first interface coupled to a client computer which manages a client side user identifier used by the client computer to identify a client computer user; a second interface coupled to a first storage storing first file system data and a first file system side user identifier used by the first file system to identify the client computer user, and a second storage storing second file system data and a second file system side user identifier used by the second file system to identify the client computer user; a processor which receives a client computer's first access request to the first file system, obtains a first file system identifier which identifies the first file system and the first file system side user identifier, and translates the first file system side user identifier to a first client side user identifier using the first file system identifier.

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 present invention relates to a migration of a file from a path denotative NAS server to an ID denotative NAS server. In a file management device a migration-use path denotative NAS access section obtains a file deposit location from the path denotative NAS server, selects a migration target file based on the deposit location, and sends a read request with the deposit location of the migration target file to the path denotative NAS server, so as to obtain the migration target file. A migration-use denotative NAS access section generates a write request with the migration target file, sends it to the ID denotative NAS servers, and writes the file therein. In addition, the migration-use ID denotative NAS access section registers a GUID received from the ID denotative NAS servers in a file name/GUID management table, together with the file name of the migration target file.

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: A storage where one NAS server makes snapshot management information including global paths of snapshots based on snapshot identifiers and global paths of file systems corresponding to the snapshots, so that global paths of both the file systems and snapshots are configured on the same global namespace simultaneously, with a directory configuration of the snapshots being the same in configuration layout as a directory configuration of the file systems; the one NAS server informs other NAS servers of the snapshot management information; memory in each of the NAS servers stores the snapshot management information; the snapshot management information includes the snapshot identifier, local path and global path for each of snapshots obtained by each NAS server at each point in time; and the computer obtains the snapshot management information from at least one of the NAS servers and displays at least a part of the snapshot management information.

Abstract: The present invention relates to a migration of a file from a path denotative NAS server to an ID denotative NAS server. In a file management device according to one embodiment, a migration-use path denotative NAS access section obtains a file deposit location from the path denotative NAS server, selects a migration target file based on the deposit location, and sends a read request with the deposit location of the migration target file to the path denotative NAS server, so as to obtain the migration target file. A migration-use denotative NAS access section 44 generates a write request with the migration target file, sends it to the ID denotative NAS servers, and writes the file therein. In addition, the migration-use ID denotative NAS access section registers a GUID received from the ID denotative NAS servers in a file name/GUID management table, together with the file name of the migration target file.

Abstract: Provided is a storage system as follows. A server holds a management table that serves to manage a mount point of a file system. The management table stores a file system identifier that uniquely identifies the file system within the storage system, mount point information that indicates the mount point of the file system, and a management server identifier that indicates an identifier of the server that manages the file system. The contents stored in the management table of each server are the same. Upon reception of a request to obtain a file handle, each server returns the file handle requested to be obtained. The file handle indicates, uniquely within the storage system, the storage area on the disk subsystem in which the file relating to the request is stored.

Abstract: A storage system including: a storage device for storing a file; a plurality of file systems for managing the file; and a plurality of NAS servers that control access from a client to the file systems via a global namespace formed by grouping local namespaces for the one or more file systems; wherein, each NAS server includes a memory to store global namespace management information including global paths of the file systems; one NAS server of the NAS servers accepts a request to obtain snapshots of the file systems from external of the storage system; the one NAS server instructs itself and the other NAS servers to obtain snapshots of the file systems; the one NAS server and the other NAS servers obtain the snapshots of the file systems, and inform the one NAS server of snapshot identifiers and of local paths of the snapshots; the one NAS server makes snapshot management information including global paths of the snapshots based on each of the snapshot identifiers received from the other NAS servers and each