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: An aspect of the invention relates to a method of managing data location of plural files in a storage system having a mixed volume which includes plural pages having a fixed page size, the pages belonging to different tiers. The method comprises mapping pages of different tiers to storage devices of different speeds in the storage system, the storage devices including at least a high speed storage device corresponding to a high tier page and a low speed storage device corresponding to a low tier page; and for each file that is a large file which is larger in size than the page size, performing sub-file tiered management on the large file to assign the large file among pages of different tiers according to access characteristics of different portions of the large file by matching the access characteristics of each portion of the large file with a corresponding tier of the assigned page of the mixed volume.

Abstract: It is an object of the present invention to provide a technique for managing, in a file system that stores past images of a data file, access right to the past images. A computer according to the present invention includes a past access control list in which access right of a user to past images and a period in which the access right is applied are described and validates accessibility to the past images using the past access control list (see FIG. 5).

Abstract: Proposed are a backup apparatus and a backup method capable of improving the backup performance, as well as a file reading apparatus capable of improving the file reading performance. As a result of determining a read sequence upon reading the respective files from a disk device based on a physical address of the respective storage areas storing data of each of the files in the disk device, and sequentially reading data of each of the files from the disk device according to the determined read sequence, overhead such as the head seek and rotational delay in the disk device upon reading a plurality of files from such disk device can be dramatically reduced.

Abstract: An epitaxial SiC single crystal substrate including a SiC single crystal wafer whose main surface is a c-plane or a surface that inclines a c-plane with an angle of inclination that is more than 0 degree but less than 10 degrees, and SiC epitaxial film that is formed on the main surface of the SiC single crystal wafer, wherein the dislocation array density of threading edge dislocation arrays that are formed in the SiC epitaxial film is 10 arrays/cm2 or less.

Abstract: A storage system comprises a storage apparatus which includes a processor, storage disks, and a memory storing a page mapping table, a page mapping program, and a page-filename mapping program. A file system manages a file tree of files with filenames. The page mapping table specifies a relationship between data volumes in the storage apparatus and the storage disks and the file system, the data volumes each including pages, each page including segments, each segment including sectors. The file tree has for each storage apparatus a hierarchy of directories and files based on relationships among the data volumes, the pages, and the segments. The page mapping program and the page-filename mapping program are executable by the processor to specify, by page, a location of data contained in the I/O request by referring to the page mapping table and the file tree.

Abstract: An epitaxial SiC single crystal substrate including a SiC single crystal wafer whose main surface is a c-plane or a surface that inclines a c-plane with an angle of inclination that is more than 0 degree but less than 10 degrees, and SiC epitaxial film that is formed on the main surface of the SiC single crystal wafer, wherein the dislocation array density of threading edge dislocation arrays that are formed in the SiC epitaxial film is 10 arrays/cm2 or less.

Abstract: A storage system comprises a storage apparatus which includes a processor, storage disks, and a memory storing a page mapping table, a page mapping program, and a page-filename mapping program. A file system manages a file tree of files with filenames. The page mapping table specifies a relationship between data volumes in the storage apparatus and the storage disks and the file system, the data volumes each including pages, each page including segments, each segment including sectors. The file tree has for each storage apparatus a hierarchy of directories and files based on relationships among the data volumes, the pages, and the segments. The page mapping program and the page-filename mapping program are executable by the processor to specify, by page, a location of data contained in the I/O request by referring to the page mapping table and the file tree.

Abstract: In an information system which includes a local site including a cache file server coupled with a host computer, and a remote site including a remote file server coupled with a surrogate processing computer, a method determines whether each of one or more files of data for a data processing request is cached or not. If yes, the method executes data processing for each cached file to produce results in local site. If no, the method includes creating a file list of files to be processed in remote site; sending the file list and processing program to the surrogate computer; if the processing is sufficiently effective to be done by the surrogate computer, receiving results of the processing executed in remote site, and, if not, then receiving an unprocessed file list from remote site and executing data processing in local site and receiving any results already executed in remote site.

Abstract: A method switches file server from old file server to new file server which are coupled via a backend network and provides data synchronization. The old file server and new file server are coupled with one or more host computers via a frontend network to direct input/output (I/O) requests from the one or more host computers. The method comprises creating stub files in the new file server, the stub files including stub information indicating location of data in the old file server; switching I/O requests directed to old file server to I/O requests directed to the new file server; checking whether the new file server has any stub files; and, if the new file server has one or more stub files, recalling data corresponding to the one or more stub files from the old file server according to the stub information to replace the one or more stub files.

Abstract: Embodiments of the invention provide methods and systems of managing a file access, in a distributed file system environment. In the provided methods and systems, each of the host computers is connected with one of the file servers as a target file server and issues the file access request to the target file server, for access to a target file stored in at least one of the file servers. The management computer collects load information from the file servers, analyzes it, by specifying location of the target file and the target file server, and based on the analysis, redistributes the target file among the file servers and reallocates connections between the host computers and the target file servers.

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: Embodiments of the invention provide object-based tier management to improve the allocation of objects to different media of different speeds based on access characteristics such as access frequency. One embodiment is directed to a method of managing object-based data in an information system which includes an application server and a storage system. The method comprises receiving a write command including a first data to be written into a virtual volume; identifying an object to which the first data corresponds; checking if a second data corresponding to the object has been stored in the virtual volume; if the second data has been stored in a page of the virtual volume, checking if the page which stores the second data has a vacancy area; and if the page has a vacancy area, writing the first data in the page which stores the second data.

Abstract: In a storage system that includes two or more file servers each including an arbitrary number of operating virtual file servers, a management server: holds a load information table regarding a load on each virtual file server for each time period and redundancy information table for the storage system; judges, with reference to the load information table and redundancy information table, whether or not the loads on the virtual file servers can be handled by a smaller number of file servers than the number of currently-operating file servers; selects, if the judgment result is positive, a power-off target file server and makes another file server fail over a virtual file server in the power-off target file server; and turns off the power-off target file server.

Abstract: In a storage system that includes two or more file servers each including an arbitrary number of operating virtual file servers, a management server: holds a load information table regarding a load on each virtual file server for each time period and redundancy information table for the storage system; judges, with reference to the load information table and redundancy information table, whether or not the loads on the virtual file servers can be handled by a smaller number of file servers than the number of currently-operating file servers; selects, if the judgment result is positive, a power-off target file server and makes another file server fail over a virtual file server in the power-off target file server; and turns off the power-off target file server.

Abstract: An aspect of the invention relates to a method of managing data location of plural files in a storage system having a mixed volume which includes plural pages having a fixed page size, the pages belonging to different tiers. The method comprises mapping pages of different tiers to storage devices of different speeds in the storage system, the storage devices including at least a high speed storage device corresponding to a high tier page and a low speed storage device corresponding to a low tier page; and for each file that is a large file which is larger in size than the page size, performing sub-file tiered management on the large file to assign the large file among pages of different tiers according to access characteristics of different portions of the large file by matching the access characteristics of each portion of the large file with a corresponding tier of the assigned page of the mixed volume.

Abstract: A storage system comprises a storage apparatus which includes a processor, storage disks, and a memory storing a page mapping table, a page mapping program, and a page-filename mapping program. A file system manages a file tree of files with filenames. The page mapping table specifies a relationship between data volumes in the storage apparatus and the storage disks and the file system, the data volumes each including pages, each page including segments, each segment including sectors. The file tree has for each storage apparatus a hierarchy of directories and files based on relationships among the data volumes, the pages, and the segments. The page mapping program and the page-filename mapping program are executable by the processor to specify, by page, a location of data contained in the I/O request by referring to the page mapping table and the file tree.

Abstract: An epitaxial SiC single crystal substrate including a SiC single crystal wafer whose main surface is a c-plane or a surface that inclines a c-plane with an angle of inclination that is more than 0 degree but less than 10 degrees, and SiC epitaxial film that is formed on the main surface of the SiC single crystal wafer, wherein the dislocation array density of threading edge dislocation arrays that are formed in the SiC epitaxial film is 10 arrays/cm2 or less.

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.