Abstract: A method, executed by at least one processor, includes generating a snapshot for a plurality of data files, receiving an update request for a selected file of the plurality of data files, determining if the selected file is subject to a backup policy, updating the selected file without preserving the snapshot of the selected file if the selected file is not subject to the backup policy, and updating the selected file while preserving the snapshot of the selected file if the selected file is subject to the backup policy. A corresponding computer program product and computer system are also disclosed herein.

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.

Abstract: A method can include obtaining write information corresponding to an index to be written to a tape. The write information can include a target write position on the tape for the index. The method can include making a first determination that the target write position is beyond a threshold position on the tape. The method can include obtaining index information comprising a size of a full index stored on the tape. The method can include making a second determination that the size of the full index exceeds a size of one dataset. The method can include writing, in response to making the first determination and the second determination, the index to the tape. The writing can be in a first position beyond the threshold position. The index can be an incremental index.

Abstract: In an approach to adaptive tape calibration criteria based on the number of stop writes, the number of rewrite occurrences caused by a stop write is determined for each specific tape drive type. Responsive to detecting a stop write during a write operation, the total number of stop writes is stored on the tape drive. A rewrite calibration threshold is determined, where the rewrite calibration threshold includes the total number of stop writes on the tape drive and a calibration reference value for the specific tape drive type. Responsive to the number of rewrite occurrences caused by the stop write exceeding the rewrite calibration threshold while writing a data set on the tape drive, a calibration of the tape drive is performed.

Abstract: An apparatus according to one embodiment includes a controller configured to control writing operations to a magnetic recording tape, and logic integrated with and/or executable by the controller for causing the controller to receive a plurality of records, store datasets associated with the plurality of records in a buffer memory, and write the datasets stored in the buffer memory to the magnetic recording tape in response to a predetermined number of datasets being stored in the buffer memory. For each of the datasets being written, an end longitudinal position indicative of a physical position where the dataset is physically written to the magnetic recording tape is determined. Moreover, for each determined end longitudinal position, the end longitudinal position and an identifier of the associated dataset are stored to a table of a dataset that is to be subsequently written to the magnetic recording 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: A method for indexing a tape for unmounting from a tape drive is discussed. The method can determine that an update has been made to the tape since it was last mounted. The method can identify a tape head position with respect to the tape, the tape including a data partition and an index partition. The method can identify first position and a second position on the tape. The method can determine first distance, a length of tape between first position and tape head position. The method can determine second distance, a length of tape between first position and second position. The method can determine that first distance is less than second distance. The method can reposition the tape to a primary section and write the metadata index. The method can reposition tape to the second position write a data index beginning at the second position of the data partition.

Abstract: Provided is a method for writing and deleting files on a tape medium and a cache storage device. The method includes receiving a command to write one or more files of a directory to a tape medium. The method further includes identifying a cache limit associated with the tape medium. The method further comprises determining whether the amount of data of the directory that is already on the cache storage device exceeds the cache limit. In response to the amount of data not exceeding the cache limit, the method includes writing data of the one or more files to the cache storage device and the tape medium in parallel.

Abstract: A computer-implemented method for indexing a tape for unmounting from a tape drive. The computer-implemented method includes: receiving a request to unmount the tape from the tape drive, wherein the tape includes an index partition and a data partition, determining that an update to the tape is not reflected in any data index written in the data partition, appending a new data index at the end of the last written data file in the data partition, wherein the new data index includes information associated with the update to the tape, unthreading the tape from the tape drive, wherein unthreading the tape from the tape drive is performed at low tension writing a metadata index to an ancillary storage device, wherein the metadata index includes information associated with the update to the tape.

Abstract: Deep learning applications access modified files stored in high speed storage. The modified files are custom formatted for use by deep learning applications to minimize file size. Parent files from which the modified files are made are stored in low speed storage as files having the original characteristics of the parent files. Requesters identified as deep learning applications are provided access to the modified files in high speed storage. Requesting applications not identified as deep learning applications receive the parent files via conventional processing from low speed storage.

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: Described are techniques for a tape unmounting protocol. The techniques include selecting a tape for unmounting from a plurality of tape drives, where the tape for unmounting includes a remaining capacity below a first threshold and a number of migrated files below a second threshold. The techniques further include unmounting the tape for unmounting from a tape drive.

Abstract: A tape drive that can select one or more wraps from any available wraps on a tape medium for writing temporary data upon detecting a flush condition. The one or more wraps selected for writing temporary data can be selected from wraps otherwise reserved for normal writing operations. Selection of the one or more wraps for temporary writing may be based on multiple considerations, including proximity to the wrap of current data writing operations and tape medium degradation. The one or more wraps selected for writing temporary data may be selected with or without regard of their assigned read/write direction. Assigning wraps based on proximity and/or degradation can lead to certain operational advantages including reducing tape write head movement in the transverse direction and spreading tape medium wear more evenly across the surface of the tape medium.

Abstract: In an approach to HRTD recovery by writing the HRTD in a null data set, responsive to receiving a request to write a data set to a magnetic tape, a lead data set of a current wrap of a plurality of wraps of the magnetic tape is written, wherein the lead data set of the current wrap includes a current wrap HRTD that contains one or more directory records for each wrap of the plurality of wraps from a lead wrap of the plurality of wraps through a first prior wrap of the plurality of wraps, and further wherein the first prior wrap immediately precedes the current wrap.

Abstract: A tape drive that can select one or more wraps from any available wraps on a tape medium for writing temporary data upon detecting a flush condition. The one or more wraps selected for writing temporary data can be selected from wraps otherwise reserved for normal writing operations. Selection of the one or more wraps for temporary writing may be based on multiple considerations, including proximity to the wrap of current data writing operations and tape medium degradation. The one or more wraps selected for writing temporary data may be selected with or without regard of their assigned read/write direction. Assigning wraps based on proximity and/or degradation can lead to certain operational advantages including reducing tape write head movement in the transverse direction and spreading tape medium wear more evenly across the surface of the tape medium.

Abstract: A tape drive that can select one or more wraps from any available wraps on a tape medium for writing temporary data upon detecting a flush condition. The one or more wraps selected for writing temporary data can be selected from wraps otherwise reserved for normal writing operations. Selection of the one or more wraps for temporary writing may be based on multiple considerations, including proximity to the wrap of current data writing operations and tape medium degradation. The one or more wraps selected for writing temporary data may be selected with or without regard of their assigned read/write direction. Assigning wraps based on proximity and/or degradation can lead to certain operational advantages including reducing tape write head movement in the transverse direction and spreading tape medium wear more evenly across the surface of the tape medium.

Abstract: A computer-implemented method, a computer program product, and a computer system for reordering a sequence of files based on compression rates in data transfer. A host determines predicted compression rates of first files that are to be saved onto a first tape, based on a relationship between compression rates and file attributes of second files that have been saved on a second tape. The host reorders a sequence of the first files stored in host cache storage and generates a new sequence of transferring the first files from the host cache storage to the tape drive hosting the first tape, based on the predicted compression rates of the first files. The host transfers the first files to the tape drive hosting the first tape and writes the first files to the first tape, according to the new sequence.

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 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, a computer program product, and a computer system for optimizing timing for migrating data. The computer system sets a migration required flag for each of first tapes, in response to determining an estimated time period required for data migration from the first tapes to second tapes being smaller than an expiration time period of the first tapes. The computer system sets the migration required flag for a respective one of the first tapes, in response to determining the estimated time period being not smaller than the expiration time period and a predetermined time period has passed for the respective one of the first tapes. Data on tapes that migration required flags are set is to be migrated to the second tapes.