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 computer-implemented method for maintaining a storage volume in a virtual tape system includes writing one or more logical volumes associated with a first category and one or more logical volumes associated with a second category to a primary storage in a virtual tape system. The computer-implemented method further includes performing a first automatic removal process in order to free up space on the primary storage, wherein the first automatic removal process removes logical volumes associated with the first category in priority to logical volumes associated with the second category. The computer-implemented method further includes performing a second automatic removal process, wherein the second automatic removal process dynamically alters the priority of the first automatic removal process such that one or more virtual volumes associated with the second category are removed in priority to one or more virtual volumes associated with the first category.

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, according to one embodiment, includes: receiving a volume at a first cluster in a first tier of a tiered data storage system. The first tier includes of a plurality of clusters, and the first cluster is coupled to a secondary storage in a second tier. A determination is made as to whether any clusters in the first tier are designated as copy target locations for the volume. In response to determining that one or more of the clusters in the first tier are designated as a copy target location, for each of the one or more clusters designated as a copy target location: a determination is made as to whether the given cluster is coupled to the secondary storage. Moreover, in response to determining that the given cluster is not coupled to the secondary storage, a copy of the volume is sent to the given cluster.

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.

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: A computer-implemented method for faster unmount of tape drives includes generating a batch file to be migrated from a primary storage to a tape media acting as a secondary storage. The size of the batch file is determined based on an amount of available storage space on the tape media between a position in a longitudinal direction of storage (LPOS) and longitudinal position three (LP3) on the tape media. The computer-implemented method further includes migrating the batch file from the primary storage to the tape media mounted on a tape drive. Upon completion of migrating the batch file, the LPOS is within a predetermined threshold distance of LP3 on the tape media.

Abstract: A storage system receives one or more records from a host system. The records are compressed in a first compression format that is native to the host system. The storage system identifies an incompatibility between the first compression format and a first operation of the storage system. In response to the identified incompatibility, the storage system decompresses the received records. The decompression is based on the first compression format. The storage system compresses the decompressed records in a second compression format. The storage system stores the secondarily compressed records onto a storage medium.

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.

Abstract: A computer-implemented method for writing data to a tape medium, includes: writing a file of a first content to the tape medium; writing at least a part of the file of a second content to the tape medium, the second content being obtained by updating the first content; and writing an index including first metadata and second metadata to the tape medium, the first metadata being metadata of the file of the first content, the second metadata being metadata of the file of the second content.

Abstract: A computer-implemented method for faster unmount of tape drives includes generating a batch file to be migrated from a primary storage to a tape media acting as a secondary storage. The size of the batch file is determined based on an amount of available storage space on the tape media between a position in a longitudinal direction of storage (LPOS) and longitudinal position three (LP3) on the tape media. The computer-implemented method further includes migrating the batch file from the primary storage to the tape media mounted on a tape drive. Upon completion of migrating the batch file, the LPOS is within a predetermined threshold distance of LP3 on the tape media.

Abstract: Aspects of the present disclosure relate to managing index writes within a tape. A determination can be made that a change was made to at least one file stored within a tape medium while the tape medium was mounted within a tape drive. In response to the determination, an index can be written to a data partition of the tape medium. A determination can be made whether the change included any changes to a file at least equal to a threshold hierarchy level. In response to determining that the change did not include any changes to a file at least equal to the threshold hierarchy level, a first instruction can be issued to the tape drive to reposition the tape medium to the end of the tape. A second instruction can be issued to the tape drive to perform an unthread operation at low tension to rewind the tape medium.

Abstract: Method, computer program product, and system embodiments of the present disclosure may include a computing device which may set a predetermined flag on data to be copied from a primary storage tier and a secondary storage tier. The computing device may identify a first portion of the flagged data as being in a pre-migrated state stored on the primary storage tier and migrate the flagged pre-migrated data from the primary storage tier to a target medium. The computing device may identify a second portion of the flagged data as being in a migrated state stored on the secondary storage tier. The computing device may recall the flagged migrated data from the secondary storage tier to the primary storage tier and migrate the recalled migrated data from the primary storage tier to the target medium.

Abstract: A computer-implemented method, according to one embodiment, includes assigning one or more first-type tape cartridges to an upper tape layer of a hierarchical storage management system, assigning one or more second-type tape cartridges to a lower tape layer of the hierarchical storage management system, and moving, to the lower tape layer, data having lower access frequency and recorded in the first-type tape cartridge assigned to the upper tape layer. A length of a tape included in the second-type tape cartridge is longer than a length of a tape included in the first-type tape cartridge.

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: 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 method for restoring a target file system in a storage system by a computer system, the computer system being connected to a network, the storage system including a tier of sequential access media, the method includes receiving a backup image including metadata of a file of the target file system, from a remote computer system via the network, the metadata indicating a sequential access medium, and restoring the metadata of the target file system using the backup image, the target file system being restored on the computer system by sharing a resource with a native file system operating on the computer system.

Abstract: A method for avoiding inode number conflict during metadata restoration at a restoration location is provided. The method includes receiving metadata for a first file including an inode containing an initial internal inode number and a directory entry containing an external inode number, determining an allocation status of the initial internal inode number at the restoration location, identifying an available internal inode number to be allocated to the first file, updating the initial internal inode number in the inode for the first file with the available internal inode number, registering the available internal inode number and the external inode number in an inode mapping table indicating correspondence between the available internal inode number and the external inode number, and restoring the inode based on the available internal inode number.

Abstract: A backup method is provided for a file system for managing hierarchical storage including one or more storage media on a computer system including one or more computers. Each of the one or more storage media includes a data part which is separated from an index and on which updated information is appended and kept. Each of a plurality of pieces of data within the file system is managed to be migrated to at least any of the one or more storage media. The backup method includes backing up metadata of the plurality of pieces of data migrated within the file system; and backing up the index of each of the one or more storage media to which the plurality of pieces of data have been migrated, substantially at the same time point as the metadata.