International Business Machines Corporation

Sosuke Matsui

Tsuyoshi Miyamura

Noriko Yamamoto

Shinsuke Mitsuma

Tohru Hasegawa

Hiroshi Itagaki

Takahiro Tsuda

Norie Iwasaki

Koichi Masuda

Kousei Kawamura

Yutaka Oishi

Terue Watanabe

Takeshi Nohta

Atsushi Abe

Michael Robert Scott

Hiroshi Araki

Jun Tanaka

Hiroyuki Miyoshi

Satoshi Takai

Aderson J Pacini

David C Reed

Katsuyoshi Katori

Eiji Tosaka

Derek Logan Erdmann

Izuru Narita

Katja I Denefleh

Ryohta Kawase

Thorsten Altmannsberger

Yuki Asakura

Erina Tatsumi

Hiroshi Itakagi

Kohichi Masuda

A computer-implemented method for altering a current position in a Data Partition of a tape at which the tape transitions to a DATA_FULL state is disclosed. The computer-implemented method includes determining a size of a last Index appended to the Data Partition of the tape. The computer-implemented method further includes altering, based on the size of the last Index appended to the Data Partition of the tape, the current position in the Data Partition of the tape at which the tape transitions to DATA_FULL state to a new position in the DATA Partition of the tape at which the tape transitions to the DATA_FULL state, wherein the DATA_FULL state is a state on the tape in which only metadata write operations are permitted in the Data Partition.

Dynamic tape storage device data buffer

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.

Tape unmounting protocol

A computer-implemented method according to one approach includes copying data stored on a Linear Tape File System (LTFS)-based storage system to blocks of a Random Access Nonvolatile Memory (RANVM) drive. The data is copied in units of the blocks of the drive. The method further includes constructing file metadata so that the copied data on the drive is accessible as one or more files. A computer program product according to another approach includes a computer readable storage medium having program instructions embodied therewith. The program instructions are readable and/or executable by a controller to cause the controller to perform the foregoing method. A system according to another approach includes a processor, and logic integrated with the processor, executable by the processor, or integrated with and executable by the processor. The logic is configured to perform the foregoing method.

Copying data from a linear tape file system (LTFS)-based storage system to a random access nonvolatile memory (RANVM) drive in units of blocks of the drive

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.

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.

Reordering files

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.

Automatic objective-based compression level change for individual clusters

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.

Backup and restoration for storage system

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).

Reducing data using a plurality of compression operations in a virtual tape library

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.

Reading sequentially stored files based on read ahead groups

In an approach, a processor determines that an inactive data area is present at end-of-tape (EOT) of a tape. A processor, responsive to determining that the inactive data area is present at EOT, securely erases the inactive data area that is present at EOT by overwriting data located at the inactive data area with different data.

Secure data erase for tape storage

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.

Copy from source medium to target medium

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.

Policy driven data updates

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.

Tape image reclaim in hierarchical storage systems

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.

Reducing data replications among storage locations

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.

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Tokyo, Japan

Sosuke Matsui