Abstract: The method, computer program product, and computer system may include a computing device which may generate a list of data to be copied from a plurality of source media to a target medium. The computing device may identify a first type of data in the generated list of data with the first type of data being pre-migrated data. The computing device may reclaim the first type of data from a primary storage tier to the target medium with the target medium being associated with the first drive. The computing device may identify a second type of data in the generated list of data, the second type of data being migrated data, and reclaim the second type of data from at least one secondary source medium to the target medium using the first drive and a second drive. The secondary source medium may be associated with the second drive.

Abstract: Aspects of the present disclosure relate to a method for timing index write to a tape medium of a tape system. Index write timing data that specifies index write timing based on file metadata attributes is stored. Metadata attributes of a first file are analyzed to determine whether a first index should be written at a first time based on the index write timing data. In response to determining that an index should be written, the first index is written to the tape medium at the first time.

Abstract: An information processing apparatus, backup method, and program product that enable efficient differential backup. In one embodiment, an information processing apparatus for files stored in a storage device includes: a metadata management unit for managing metadata of files stored in the storage device; a map generation unit for generating a map which indicates whether metadata associated with an identification value uniquely identifying a file in the storage device is present or absent; and a backup management unit for scanning the metadata to detect files that have been created, modified, or deleted since the last backup, and storing at least a data block and the metadata for a detected file in a backup storage device as backup information in association with the identification value.

Abstract: A tape drive-implemented method, according to one embodiment, includes: detecting a read error, and sending one or more instructions to perform a first re-read attempt on a portion of a magnetic tape corresponding to the read error. In response to determining that the first re-read attempt was unsuccessful, a range of tension settings is selected. A range of lateral offsets is also selected. Moreover, one or more instructions are sent to apply each unique combination of a tension setting from the range of tension settings and a lateral offset from the range of lateral offsets. For each of the unique combinations applied, one or more instructions are sent to perform a second phase re-read attempt on the portion of the magnetic tape corresponding to the read error. Furthermore, a determination is made as to whether the second phase re-read attempt was performed successfully for any of the unique combinations.

Abstract: A computer-implemented method, according to one embodiment, includes: sending one or more instructions to calculate a combined size of fragments included in the fragmented files, sending one or more instructions to designate a portion of cache which corresponds to at least the combined size of the fragments, sending one or more instructions to send a copy of each non-fragmented file from a first drive directly to a second drive in which the second sequential storage medium is loaded, sending one or more instructions to use the designated portion of the cache to accumulate the fragments included in the fragmented files, and sending one or more instructions to send a copy of each of the fragments corresponding to a given fragmented file from the cache to the second drive in response to determining that all of the fragments corresponding to the given fragmented file have been accumulated in the cache.

Abstract: Provided is a method, computer program product, and system for handling seek commands for a tape drive. The method includes receiving a seek command for moving tape in the tape drive to a target position. The method further includes moving the tape from the current position to a high water mark (HWM) with the tape at a first tension and moving the tape from the HWM to the target position with the tape at a second tension. The method further includes updating the HWM to reference the target position.

Abstract: The time required for recalling the file is reduced when the file is written in a mounted plurality of tapes in comparison to recalling the file when written in a non-mounted plurality of tapes. In the non-mounted state, criteria does not typically exist in order to recall the written file within the plurality of tapes. Embodiments of the present invention provide systems and methods for recalling files based on criteria which considers: the mounted state of a tape; the type of tape; the type of available tape drive; the number of files included in a tape; and the location of the written file in a tape.

Abstract: A linear tape file system (LTFS) maintains a series of indexes, and an incremental change dataset, that records incremental changes that have taken place in each new index over the previous one, as each new index of the series is created. Upon receiving a command to roll back the file system from a current generation to a target previous generation, a generation control module applies information in the incremental change dataset to the current index. In this way, the current index is restored, at least functionally, to the state it was in when the target generation was created, thereby effectuating the rollback of the file system to the target generation.

Abstract: In one aspect of the present invention, an apparatus includes a head configured to write data to a tape, and a hardware controller coupled to the head. The controller is configured to cause the apparatus to copy a second data area on the tape as a third data area, the second data area corresponding to data in a first data area that has changed. The controller is also configured to cause the apparatus to store, on the tape, index information for identifying the third data area, and copy the first data area to the tape as a fourth data area separate from the third data area. The controller is also configured to cause the apparatus to store, on the tape, index information for identifying the fourth data area.

Abstract: A method includes setting a maximum total size of data saved in a snapshot area, creating a snapshot of a file system, including reference to a plurality of logical volumes, saving at least a part of the plurality of logical volumes in the snapshot area on condition that it does not exceed the maximum total size of data saved in the snapshot area, and executing copy-on-write processing in response to a writing request for data in the file system, the data not being saved in the snapshot area.

Abstract: A method to identify data elements conforming to a policy includes receiving a request to identify data elements in an input set of data elements that conform to one or more requested policies. According to the method, policy output information describing data elements that conform to a requested policy are saved in association with the requested policy. In response to receiving a subsequent request to identify data elements in a subsequent set of data elements that conform to the requested policy, the method includes outputting the saved policy output information based on the policy output information having been saved in association with the requested policy. A computer program product and a system, configured with processors and a memory that can store saved policy information, can implement the method.

Abstract: The direction of a WRAP and the logical points on which a file are written influence the efficiency of a recall of the file. Embodiments of the present invention provide methods and systems which can be applied to an upper storage layer and a lower storage layer in a hierarchical storage system. In turn, the migration and recall of a plurality of files, which contain data, are more rapid and efficient by preferring one logical point over another logical point.

Abstract: A method, computer system, and a computer program product for verifying data written to a tape is provided. The present invention may include preparing a first group of data to be written to the tape; signaling a tape drive to perform a write operation to write the first group of data to the tape; receiving from the tape drive a tape head location signal, wherein the tape head location signal indicates that the tape drive has detected that the tape movement during the write operation has reached a turnaround point; performing a read operation to read the first group of data from the tape; receiving from the tape drive a second group of data read by the tape drive during the read operation; and comparing the first group of data to the second group of data.

Abstract: A method and system for a controlling a head element of a tape drive is disclosed. Y-position values based on servo bands are identified. Control adjustments for the head element are determined based on the Y-position values and the direction of the current wrap.

Abstract: According to one embodiment there is provided a method for managing a location of an object in a storage system having hierarchical storage with a plurality of storage layers. The method includes transmitting a get-list request for viewing contents of a designated directory on the hierarchical storage. The method also includes receiving a response to the get-list request, the response including a list of objects in the designated directory and listing each storage layer corresponding to the objects. The list is output, and a select request to select a different storage layer for one of the objects is received. The select request is transmitted to the storage system for invoking migration of the selected object to the different storage layer. A second response is received from the storage system indicating the selected object is stored in the different storage layer, and an updated list is output.

Abstract: A computer-implemented method for managing a first storage library and a second storage library, according to one embodiment, includes associating a first physical tape and a second physical tape with a logical tape. The associating includes writing a first identifier to an index of the logical tape. The first identifier represents the first physical tape and the first storage library. The associating further includes writing a second identifier to the index of the logical tape. The second identifier represents the second physical tape and the second storage library. The computer-implemented method further includes storing the index of the logical tape in memory, and displaying the logical tape by reading the index from memory as a file system.

Abstract: A computer program product, according to one embodiment, includes a computer readable storage medium having program instructions embodied therewith. The program instructions are readable and/or executable by a processor to cause the processor to: determine, by the processor, a first error location on a magnetic tape where a first error occurred. One or more areas on the magnetic tape to be examined are also determined, by the processor, based on the first error location. Independent of a read and/or write operation, relative motion between a tape head and the magnetic tape is induced by the processor, such that the tape head is positioned adjacent to each of the one or more areas in turn. Moreover, each of the one or more areas having a respective number of measured servo errors which exceeds a threshold value are identified, by the processor, as a damaged area of the magnetic tape.

Abstract: A computer-implemented method, according to one embodiment, includes: receiving, from a tape drive, a first error location on a magnetic tape where a first error occurred, in addition to determining one or more areas on the magnetic tape to be examined based on the first error location. Independent of a read and/or write operation, the tape drive is instructed to induce relative motion between a tape head and the magnetic tape such that the tape head is positioned adjacent to each of the respective one or more areas in turn. Moreover, each of the one or more areas having a respective number of measured servo errors which exceeds a threshold value is identified as a damaged area of the magnetic tape.

Abstract: A computer-implemented method, according to one embodiment, includes: estimating, by the computer system, a waiting time for copy target data to be transferred from the source medium. The waiting time includes an estimated time for locating and reading the copy target data from the source medium. The method also includes selecting, by the computer system, migration target data on the source medium based on whether migration of data to the target medium is expected to be finished within the waiting time. The selecting is based at least in part on comparing a size of the data and an allowable size calculated based on the waiting time and an estimated write transfer rate to the target medium. The method further includes migrating, by the computer system, the migration target data from the source medium to the target medium.

Abstract: A computer-implemented method for performing a storage reclaim on a storage device includes generating a second tape image on a first storage device. The computer-implemented method further includes copying metadata associated with a first data extent of a valid file from a first index partition of a first tape image to a second index partition of the second tape image. The computer-implemented method further includes copying file data associated with the first data extent from a first data partition of the first tape image to a second data partition of the second tape image. The computer-implemented method further includes adjusting metadata associated with the file data of the first data extent copied to the second data partition of the second tape image. The computer-implemented method further includes releasing a storage area corresponding to the first data extent of the valid file included in the first tape image.