Abstract: A method, executed by a computer, for recording data includes splitting a file into sequential extents, reordering the sequential extents into non-sequential extents, writing the non-sequential extents to a storage medium, writing dummy data to the storage medium, and writing extent placement information corresponding to a placement for the non-sequential extents to the storage medium. A computer program product and computer system corresponding to the above method are also disclosed herein.

Abstract: A computer-implemented method for copying data from a source medium to a target medium in a storage system by a computer system, the storage system including a storage device, a first drive configured to access the source medium, and a second drive configured to access the target medium, the method comprising: estimating a waiting time for copy target data to be transferred from the source medium, selecting migration target data of the storage device based on whether migration of data to the target medium is expected to be finished within the waiting time or not, migrating the migration target data from the storage device to the target medium by the second drive while locating and/or reading the copy target data on the source medium by the first drive, and writing the copy target data to the target medium by the second drive.

Abstract: In a general embodiment, a method includes storing hierarchically-organized global configuration information for each node and each tape library resource in a storage cluster to at least one memory accessible by each node of the storage cluster, the storage cluster comprising at least one tape library. The method further includes migrating and/or recalling, using the hierarchically-organized global configuration information, data to and/or from a tape cartridge pool within a tape library. The migration or recall is performed by an appropriate node of the storage cluster and in response to receiving a migration or recall request at an arbitrary node of the storage cluster.

Abstract: One or more processors receive data records from a file system, and convert the data records to a tape image having a format defined by the file system. The tape image is written to a first storage device, and a sequence of data types of the first storage device and a second storage device are monitored to determine whether the first storage device sequence of data types differs from the sequence of data types of the second storage device. Determining that the sequence of data types of the first storage device and second storage device do differ, one or more processors copying, to the second storage device, the data records from the first storage device, from the position on the first storage device that corresponds to the end-of-data position of the second storage device, to the end-of-data position of the first storage device.

Abstract: A file system to controls access to a tape library that selectively loads and unloads a plurality of cartridges from a plurality of slots to a drive for transmitting to the file system archived data retrieved from a particular cartridge. The file system includes a cache and receives a request from a requestor to access the tape library, estimates a first data transfer rate from an anticipated tape library operation completion duration and from a capacity of cached data to be transmitted from the cache to the requestor, initiates access to the tape library, and adapts the first data transfer rate to a second data transfer rate to transmit the capacity of the cached data to the requestor throughout the anticipated tape library operation completion duration.

Abstract: In one embodiment, a storage system configured for reading a file written to a plurality of tape media includes at least two tape drives and a read/write control. The read/write control is configured to load a tape medium into a tape drive, and read metadata from the loaded tape medium and determine from the metadata whether the tape medium is a parent tape medium or a child tape medium for the file. The read/write control is also configured to retrieve ID information on the parent tape medium from the metadata saved in the child tape medium in response to a determination that the loaded tape medium is a child tape medium, and load the parent tape medium identified by the retrieved ID information into another tape drive. Moreover, the read/write control is configured to read a written first file part based on metadata saved in the loaded parent tape medium.

Abstract: In an approach for writing data on a tape using a file system, a processor receives a first write request of a first file. A processor obtains data of the first file. A processor writes the data of the first file on a tape. A processor receives a second write request of a second file prior to completion of writing the data of the first file on the tape. A processor adds information about the second file to a first list, wherein the first list includes files waiting to write. Subsequent to writing the data of the first file on the tape, a processor obtains data of the second file based on the first list. A processor writes the data of the second file after the first file on the tape.

Abstract: A mechanism is provided for improved file synchronization of a magnetic tape. A destination device determines whether one or more file checksums exist in an extended file attribute associated with an identified file. Responsive to one or more file checksums existing in the extended file attribute associated with the identified file, the destination device reads the one or more file checksums out of the extended file attribute without accessing the magnetic tape. The destination device transmits the one or more file checksums to a source device. The source device segments the data of the new file into fixed-length blocks that do not overlap one another. The source device calculates one or more new file checksums for each of the fixed-length blocks. The source device transmits the one or more new file checksums to the destination device.

Abstract: According to one embodiment, a method for writing a file to a plurality of media includes loading a parent medium into a first drive to retrieve ID information about the parent medium from metadata, writing a first file part to the parent medium and, at about a same time, saving a file name, attribute information, and attribute information about the first file part to the parent medium as metadata, loading a child medium into a second drive in order to write subsequent file parts and retrieving ID information about the child medium from metadata, writing the subsequent file parts to the child medium and, at about a same time, saving the ID information and attribute information about the subsequent file parts to the parent medium, and additionally saving the ID information about the child medium and the attribute information about the subsequent file parts as metadata in the child medium.

Abstract: According to one embodiment, a method includes presenting a medium to more than one user as being exclusively occupied by whichever user attempts to access at least one file from the medium, writing a first file managed by a first user to a data partition of the medium, and storing a first user identifier (ID) that identifies the first user as metadata to an index partition of the medium in response to writing the first file managed by the first user. In another embodiment, a method includes reading metadata from an index partition of a medium from a first user of a plurality of users, extracting first file attribute information associated with a first user ID that indicates a first user from the metadata, and reading a first file based on the first file attribute information associated with the first user ID from a data partition of the medium.

Abstract: A mechanism is provided for improved file synchronization of a magnetic tape. A destination device determines whether one or more file checksums exist in an extended file attribute associated with an identified file. Responsive to one or more file checksums existing in the extended file attribute associated with the identified file, the destination device reads the one or more file checksums out of the extended file attribute without accessing the magnetic tape. The destination device transmits the one or more file checksums to a source device. The source device segments the data of the new file into fixed-length blocks that do not overlap one another. The source device calculates one or more new file checksums for each of the fixed-length blocks. The source device transmits the one or more new file checksums to the destination device.

Abstract: An information providing system and method, including a computer, for providing time taken to read a file, which includes an acquisition unit. The acquisition unit obtains information on a recording position of a file when the file is recorded in a storage device. A recording unit writes information on the obtained recording position to an index referred to access the file. A calculation unit calculates time taken to read the file using the information on the recording position written to the index in response to a request to obtain the time taken to read the file, and providing the calculated time to a requester that requests the time.

Abstract: In a controller of a tape drive, when an error recovery section cannot recover an error detected by an error detecting section, an error-report generation section generates an error report, an error-information acquisition section acquires error information of the tape drive and a cartridge loaded in the tape drive, an error-information exchange section acquires pieces of error information of other tape drives and cartridges loaded in these other tape drives, an error-factor judging section judges whether the error is attributable to the tape drive or the cartridge based on these pieces of error information, an error-report update section updates the error report in accordance with the result of this judgment, and an error-report output section outputs the error report thus updated to a host.

Abstract: Rolling back data on tape in a file system is provided. A management tape is prepared. The management tape has only index files recorded thereon. The index files contain information about start positions and lengths of corresponding data files recorded on normal tapes. The index files further contain identification information for the normal tapes. A first index file of the management tape is read. The first index file is related to a data file to be rolled back. The first index file is read out from the management tape mounted on a first tape drive. The data file to be rolled back is read out of a first normal tape. The first normal tape is identified based on information in the first index file. The first normal tape is mounted on a second tape drive.

Abstract: According to one embodiment, a method for a plurality of users to write at least one file to a medium in such a manner that the file is divisionally managed in a system environment in which an input/output control is performed on a storage system includes saving, in the medium as metadata, a user identifier (ID) for identifying a user and file attribute information about the file managed by a user associated with the user ID, and writing, as data, the file managed by the user to the medium as indicated by the file attribute information. In other embodiments, a writing program product, a reading program product, and a system are presented that allow a plurality of users to write at least one file to a medium in such a manner that the file is divisionally managed in a system environment.

Abstract: A capability to store meta-information related to file access histories on tape recording systems is provided. Base meta-information is stored on a tape. The base meta-information is meta-information that is associated with one or more files that are stored on the tape and is based, at least in part, on a tape access operation history. A first quantity of differentiated meta-information is stored on the tape at a predetermined time interval after storing the base meta-information, wherein the first quantity of differentiated meta-information is based, at least in part, on the tape access operation history and reflects a history of at least one file of the one or more files that are associated with the base meta-information.

Abstract: A storage system includes a plurality of tape drives connected to a host, and a buffer configured to temporarily hold data read from the drives. A mechanism loads a plurality of media on which a file has been written to the plurality of drives so as to mount the plurality of media in the plurality of drives and divides the file into a plurality of data portions in an order. The mechanism determines a medium that takes the shortest time to move from a current position of a read head of a corresponding drive to a beginning position of the file and one or more media from which following data portions of the beginning data portion are to be read. The mechanism executes reading of the following data portions from the next media and temporarily holding of the read following data portions in the buffer of the storage system while reading the beginning data portion of the file from the first medium to the host.

Abstract: Managing a file on a tape. In response to a request to write a first file to a tape, whether a second file including data identical to the first file already exists on the tape is detected. If the second file exists, a first index of the second file is updated. After completing the write of the first file, metadata, including data starting position and size of the first file, is added to the first index. In response to a request to read the first or second files, the metadata of the first and second indexes are read. Based on the metadata, which of the first or second files can be accessed faster from a current head position is determined. The first file or the second file that can be accessed faster is then read from the tape.

Abstract: Provided is a method for recording data to a tape medium in such a manner as to achieve the easy management of mutually related multiple data pieces. First data and second data continuously received as a file from a higher level apparatus are accumulated in multiple buffer segments in the form of multiple successive data sets. A data structure is determined for each of the accumulated data sets. Management information indicating a result of the determination is added to the data sets, and the data sets and the management information thereof are stored into the tape medium.

Abstract: An approach to reducing overhead to enable high-speed writing even when a large number of small-sized files are written onto a tape in a file system. The method of the present invention includes the steps of: writing multiple files consecutively onto a tape to become one combined file; writing, onto the tape, first index information including the start position and size of the combined file on the tape; and writing, onto the tape, second index information including the start position and size of each of the multiple files in the combined file on the tape.