Abstract: A method includes, for files in a storage system requested in sequence by an application, identifying a pre-file and identifying a post-file requested after the pre-file. The method also includes incrementing a pre-read count for the pre-file in file attributes associated with the pre-file and incrementing a post-read count for the post-file in file attributes associated with the post-file. The method includes selecting a position in a save list for each file based on the pre-read and post-read counts and saving the files on tape media according to the relative positions of the files in the save list. A computer program product includes one or more computer readable storage media and program instructions collectively stored on the one or more computer readable storage media. The program instructions includes program instructions to perform foregoing method. A system includes a processor and logic configured to perform the foregoing method.

Abstract: A data storage change is received for a piece of data, wherein the data storage change is from a first location to a second location. Two or more possible paths to perform the data storage change are determined. A plurality of weights for each path of the two or more paths is determined. A weighted transfer time for each path of the two or more paths is determined.

Abstract: A method, computer system, and a computer program product for objective-based compression level change is provided. The present invention may include storing a volume in a storage device, wherein the stored volume is compressed using an initial compression level. The present invention may also include checking a last access time of the stored volume in the storage device at a regular interval. The present invention may further include, in response to determining, based on the checked last access time, that the stored volume is not accessed at the regular interval, recompressing the stored volume in the storage device using a higher compression level, wherein the higher compression level includes a higher compression ratio than a compression ratio associated with the initial compression level.

Abstract: Embodiments are disclosed for a method. The method includes migrating a file to a newer tape. The file is previously recalled by a linear tape file system (LTFS) from an older tape. The method also includes updating a stub for the file with metadata describing the newer tape, the older tape, and the file. Further, the method includes recalling the file using a tape selected from a plurality of potential tapes identified by the metadata.

Abstract: In an approach to improve magnetic tape file systems through tape-to-tape copying between nodes on a Linear Tape File System using a cluster-wide named pipe. Embodiments transfer data between a first node and a second node. Additionally, both the first node and the second node implement a parallel shared-disk file system through a data path for node data reading and writing from a shared-disk and to the shared-disk. Further, to transfer data between the first node and the second node, embodiments, write, by the first node, the data for tape-to-tape copy from a first tape drive to the shared-disk, and write, by the second node, the data written from the shared-disk to a second tape drive.

Abstract: A tool for tape library hierarchical storage management. The tool mounts a tape cartridge to a tape drive to satisfy a recall request. The tool determines there is available tape capacity on the tape cartridge to migrate data from a migration queue during recall operations. The tool sends a locate end of data (EOD) command to the tape drive. The tool receives a longitudinal position (LPOS) range returned from the tape drive. The tool determines the migration queue is within the LPOS range. The tool writes data from the migration queue to the tape cartridge within the LPOS range.

Abstract: Embodiments are disclosed for a method. The method includes migrating a file to a newer tape. The file is previously recalled by a linear tape file system (LTFS) from an older tape. The method also includes updating a stub for the file with metadata describing the newer tape, the older tape, and the file. Further, the method includes recalling the file using a tape selected from a plurality of potential tapes identified by the metadata.

Abstract: In an approach to improving write performance by enabling host data transfer immediately after a reposition command, responsive to receiving on a tape drive a reposition command from a host, a ready response is returned to the host. Write data from the host is accumulated in a write buffer, where the write data is accumulated in the write buffer while simultaneously moving a tape media in the tape drive to a target location. The write data from the write buffer is written to the tape media immediately after the target location is reached on the tape drive.

Abstract: An approach for improving the writing an index file on tape storage by switching, via a tape drive, write sequences in an index partition, in which the tape drive switches between a normal wrap sequence and a reverse wrap sequence. Further, embodiments write the index information by the normal wrap sequence during initialization of the tape media, in which the tape media is being mounted for the first time. Additionally, embodiments write the index information by the reverse wrap sequence during an unmounting the tape media for the first time, and wherein the tape media is mounted based on index information written at a rearmost end of one or more data partitions during second and subsequent mounting.

Abstract: A data storage change is received for a piece of data, wherein the data storage change is from a first location to a second location. Two or more possible paths to perform the data storage change are determined. A plurality of weights for each path of the two or more paths is determined. A weighted transfer time for each path of the two or more paths is determined.

Abstract: Provided is a method, computer program product, and system for enumerating files on a tape medium and a cache storage device. The method includes receiving a command to enumerate a directory stored on a tape medium. The directory includes a plurality of files. The method further includes determining that the directory has been at least partially cached to a cache storage device. The method further includes determining, for each file of the directory that is stored in the cache storage device, whether the file has been enumerated. In response to determining that the file has not been enumerated, the method includes returning information of the file as a response to the command. The method further includes mounting the tape medium in parallel to retrieving data from the cache storage device.

Abstract: A computer-implemented method for duplexing data from multiple files systems onto a shared tape is disclosed. The computer-implemented method includes receiving a unique identifier of a first tape image written to a primary storage device of a first client system. The computer-implemented method further includes determining that a position of a first end-of-data marker on the first tape image differs from a position of a second end-of-data marker on a tape corresponding to the unique identifier of the first tape image. Responsive to determining that the position of the first end-of-data marker on the first tape image differs from the position of the second end-of-data marker on the tape corresponding to the unique identifier of the first tape image, the computer-implemented method further includes copying a difference in data between the second end-of-data marker on the tape and be first end-of-data marker on the first tape image to the tape.

Abstract: In an approach to automatically reclassifying files in an HSM system, responsive to occurrence of a recall to move a file on a hierarchical storage system from a secondary storage to a primary storage, whether stub metadata exists for the file is determined. Responsive to determining that stub metadata exists for the file, whether reclassification of the file is necessary is determined based on the stub metadata. Responsive to determining that the reclassification of the file is necessary, the file is reclassified, where the reclassification uses a latest classification model, and further where the stub metadata is updated with results of the reclassification. The file is migrated from the primary storage to the secondary storage based on the stub metadata.

Abstract: Embodiments are provided for reducing data using a plurality of compression operations in a computing storage environment. A speed of data writing to a virtual tape device and an availability of one or more processor devices for the virtual tape device may be monitored. One or more requests may be received for writing data to the virtual tape device. Data to be written to the virtual tape device, corresponding to a selected number of the one or more requests for writing the data, may be compressed according to both the speed of data writing to the virtual tape device and the availability of one or more processor devices for the virtual tape device. The compressed data may be stored in the virtual tape device in record units. Non-compressed data may be compressed in the virtual tape device at a subsequent period of time (e.g., future time period).

Abstract: An approach for improving the writing an index file on tape storage by switching, via a tape drive, write sequences in an index partition, in which the tape drive switches between a normal wrap sequence and a reverse wrap sequence. Further, embodiments write the index information by the normal wrap sequence during initialization of the tape media, in which the tape media is being mounted for the first time. Additionally, embodiments write the index information by the reverse wrap sequence during an unmounting the tape media for the first time, and wherein the tape media is mounted based on index information written at a rearmost end of one or more data partitions during second and subsequent mounting.

Abstract: In an approach to automatically reclassifying files in an HSM system, responsive to occurrence of a recall to move a file on a hierarchical storage system from a secondary storage to a primary storage, whether stub metadata exists for the file is determined. Responsive to determining that stub metadata exists for the file, whether reclassification of the file is necessary is determined based on the stub metadata. Responsive to determining that the reclassification of the file is necessary, the file is reclassified, where the reclassification uses a latest classification model, and further where the stub metadata is updated with results of the reclassification. The file is migrated from the primary storage to the secondary storage based on the stub metadata.

Abstract: A plurality of files are stored on magnetic tape having at least one wrap for storing data sets. Each data set includes one or more records. A number of data sets that will remain in a buffer memory after performing a read ahead operation is determined. A number of records that are likely to remain in the buffer memory after performing a read ahead operation is determined. For each record likely to remain in the buffer memory after performing a read ahead operation, positions of the records on the magnetic tape are determined. Each file of the plurality of files are classified into one group of a plurality of groups based on a position of a record corresponding with each respective file and the number of records that are likely to remain in the buffer memory after performing a read ahead operation.

Abstract: An embodiment of the invention may include a method, computer program product and system for saving data received from a host computing device to a storage system. The storage system includes at least one processor and at least one storage. An embodiment may include storing the received data to the storage on a record basis. A record includes a record header including information indicative of an implemented compression method of the record. An embodiment may include monitoring a processing load of the at least one processor. In response to the processing load being less than a predetermined level, an embodiment may include further compressing the record utilizing a high-ratio compression method based on the record requiring further compression. An embodiment may include updating the record header information to reflect details of the utilized a high-ratio compression method. An embodiment may include storing the further compressed record to the storage.

Abstract: Aspects of the present disclosure relate to a method for reducing repositioning time within tape systems. A request to reposition to a target file within a tape medium can be received. A determination can be made that a previous command issued to the tape system was a write and that an index corresponding to the write has not been written. In response to determining that the previous command was the write and that the index corresponding to the write has not been written, a first file mark, the index after the first file mark, and a second file mark after the index can be written.

Abstract: A computer-implemented method for altering a position on a tape at which the tape transitions to a DATA_FULL state is disclosed. The computer-implemented method further includes determining, after a file is written to a Data Partition of the tape, a size of an Index representing metadata associated with the file. The computer-implemented method further includes altering, based on the size of the Index representing metadata associated with the file, a position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state.