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: A storage apparatus and method of controlling same which, while preventing depletion of a storage area due to the generation of garbage, also prevent a drop in response performance from the perspective of the host, are proposed.

Abstract: A storage apparatus and method of controlling same which, while preventing depletion of a storage area due to the generation of garbage, also prevent a drop in response performance from the perspective of the host, are proposed.

Abstract: Chunk de-duplication performance is improved. A de-duplication system has a cut-out processing unit which inputs a content from a client terminal thereinto, determines a calculation range from a predetermined maximum chunk size and a predetermined minimum chunk size, divides the calculation range into at least two small calculation ranges, sets the positions of windows for rolling hash calculation so that the rolling hash calculation is continuous between the two small calculation ranges, and subjects the at least two small calculation ranges to the rolling hash calculation with shifting of the windows based on parallel processing to cut out a chunk from the content, and a de-duplication processing unit which does not store the cut-out chunk into a storage device when the chunk having the same contents as those of the cut-out chunk is already stored in the storage device.

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: 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: Chunk de-duplication performance is improved. A de-duplication system has a cut-out processing unit which inputs a content from a client terminal thereinto, determines a calculation range from a predetermined maximum chunk size and a predetermined minimum chunk size, divides the calculation range into at least two small calculation ranges, sets the positions of windows for rolling hash calculation so that the rolling hash calculation is continuous between the two small calculation ranges, and subjects the at least two small calculation ranges to the rolling hash calculation with shifting of the windows based on parallel processing to cut out a chunk from the content, and a de-duplication processing unit which does not store the cut-out chunk into a storage device when the chunk having the same contents as those of the cut-out chunk is already stored in the storage device.

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: 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.

Abstract: It is provided a storage system including a storage device for storing data, and a controller for controlling data read/write in the storage device. The controller includes a processor for executing a program, and a memory for storing the program that is executed by the processor. The processor executes deduplication processing for converting a duplicate part of data that is stored in the storage device into shared data, and calculates a distributed capacity consumption, which represents a capacity of a storage area that is used by a user in the storage device, by using a size of the data prior to the deduplication processing and a count of pieces of data referring to the shared data that is referred to by this data.

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 server system includes a server apparatus transmitting and receiving file data based on an access request transmitted from a client apparatus; and a management apparatus managing the server apparatus, wherein the server apparatus includes a plurality of virtual server parts controlling transmission and reception of the data independently for each of the predetermined client apparatuses; a data flow configuration part configuring a data flow for each of the file data transmitted to and received by the virtual server parts based on a command from the management apparatus; and a load control part controlling a data flow for each of the file data to control load of the virtual server parts based on the data flow for each of the file data configured by the data flow configuration part.

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: 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.

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.

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: It is provided a storage system including a storage device for storing data, and a controller for controlling data read/write in the storage device. The controller includes a processor for executing a program, and a memory for storing the program that is executed by the processor. The processor executes deduplication processing for converting a duplicate part of data that is stored in the storage device into shared data, and calculates a distributed capacity consumption, which represents a capacity of a storage area that is used by a user in the storage device, by using a size of the data prior to the deduplication processing and a count of pieces of data referring to the shared data that is referred to by this data.

Abstract: A file server is replaced efficiently. A computer system includes a first file server, a second file server, and a third file server. The first file server retains file data storage information which indicates, for each file, whether data of the relevant file is stored in a first storage device or not; and after a data input/output request from a client terminal is switched from the first file server to the third file server, the third file server selects either the first file server or the second file server as a data transfer request destination of a target file of the data input/output request from the client terminal, based on the file data storage information sent from the first file server.

Abstract: When a management screen for conducting management operation of a file system in the NAS apparatus 10 of a file server is displayed by the administrator on a display device of the management console 30 by using the management console 30, if a disk device obtained from the storage apparatus 20 is in a power saving state, the NAS apparatus 10 has a function to change the operations hereafter. Specifically, a screen is displayed on the management screen, in which a creation or deletion of the file system becomes impossible with respect to the disk device in the power saving state. Therefore, the administrator can conduct management operations for services without referring to the power status, thereby resulting in easy management operation.

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.