International Business Machines Corporation

Dsm IP Assets B.v.

Roche Vitamins Inc.

Setsuko Masuda

Tsuyoshi Miyamura

Yutaka Oishi

Terue Watanabe

Atsushi Abe

Takashi Ashida

Kenji Nakamura

Hiroshi Itagaki

Yuhko Mori

Tatsuki Sawada

Keisuke Tanaka

Hirokazu Nakayama

Takamasa Hirata

Mitsuhiro Nishida

Yumiko Ohta

Nhan Xuan Bui

Kazuhiro Tsuruta

Takashi Katagiri

Tatsuo Hoshino

Pamela Ruth Nylander-Hill

Takeshi Ishimoto

Masahide Washizawa

Noriko Yamamoto

Eiji Ogura

Tomoko Taketomi

Hironobu Nagura

Yutaka Setoguchi

Motoko Oe

Katsumi Yoshimura

Aspects of the present disclosure relate to improved tape repositioning. Information associated with at least one preceding dataset on a tape medium is stored within a dataset information table (DSIT) of a dataset on the tape medium. A repositioning request specifying a target data position is received. The information associated with the at least one preceding dataset within the DSIT of the dataset is referenced while attempting to complete the repositioning request.

Tape drive repositioning

A computer-implemented method, a computer program product, and a computer system for repositioning operation on a tape medium based on dataset information. A computer system obtains dataset information of a dataset on a tape medium in a sync operation, where the dataset information includes positions of data in the dataset. A computer system sends the dataset information of the dataset to a host. In response to starting a repositioning operation, a computer system receives from the host the dataset information of the dataset. A computer system reads the dataset information of the dataset. A computer system repositions to a target on the tape medium, based on the dataset information of the dataset, where a tape drive refers to the dataset information and moves to a position immediately before the target.

Repositioning operation on a tape medium based on dataset information

A method for writing to tape by a tape drive is provided. The method includes, in response to identifying a write error during a write to a tape in a certain HRTD region, repositioning the tape to a next HRTD region. The method further includes continuing the write at the next HRTD region.

Tape drive write across write error

A system for recalling data from tape is disclosed. The system includes computer processing circuits and computer readable storage media having computer executable instructions. When executed, the instructions cause the computer-processing circuits to start, in response to a request to recall data from a tape, to read the tape at a read position. Additionally, the instructions cause the circuits to determine that the tape comprises a damaged region. Further, the instructions cause the circuits to determine a start position of the damaged region by skimming the tape. Additionally, the instructions cause the circuits to determine an end position of the damaged region by skimming the tape. Further, the instructions cause the circuits to read between the read position and the start position of the damaged region. Additionally, the instructions cause the circuits to read between the end position of the damaged region and an end of data indicator.

Recalling data from tape

A method for creating a Full Data Set Directory (FDSD) entry, in accordance with one embodiment, includes acquiring a record count and file mark count of a data set written to and/or to be written to a magnetic recording tape. A writing position on the tape where the data set will be written is determined. The data set is written on the tape. An FDSD entry is generated for the data set. The FDSD entry includes information about each of the following: a tape write pass in which the data set is written, a position of the data set on the tape, the record count, and the file mark count.

Full data set directory for magnetic tape recording media

Provided is a system, method, and computer program product for minimizing high resolution tape directory (HRTD) recovery time when a HRTD is invalid. A tape drive may load a tape in the tape drive. In response to receiving a write command or a read command at a beginning of tape (BOT) position, the tape drive may execute the write command or the read command without performing HRTD recovery. In response to receiving the write command or the read command at a position other than the BOT position, the tape drive may determine if the HRTD is valid. In response to determining the HRTD is not valid, the tape drive may clear a timer.

Minimizing high resolution tape directory recovery time

Embodiments of the present invention provide a system, method, and computer program product for offsetting a reading head on a magnetic tape to improve verification. A processor determines a write head width, a read head width, and a track pitch based on determining an LTO standard of the magnetic tape. The processor determines a distance of the reading head from a writing head using the write head width, the read head width, and the track pitch, and causes a tape appliance to relocate the read head on the magnetic tape to the determined distance.

Reducing deviation of read head position between writing and reading in a magnetic tape

A tool for scaling media utilizing healthy regions of a data storage cartridge. The tool determines a health status index for one or more regions of a data storage cartridge. The tool records the health status index to a cartridge memory and housekeeping dataset of the data storage cartridge. The tool determines one or more available regions of the data storage cartridge, based, at least in part, on a capacity designation and the health status index for the one or more regions. The tool returns the one or more available regions and a reduced capacity for the data storage cartridge to a user.

Scaling media utilizing healthy regions of a tape cartridge

In an approach to using a cut and paste segment for reading an sHKDS, a request to reposition a tape media in a tape drive is received. Responsive to encountering an error reading an sHKDS while attempting to reposition the tape media, one segment of a plurality of segments from a data set cut and paste error recovery procedure (ERP) is used for an sHKDS cut and paste ERP. Responsive to recovering the sHKDS using the sHKDS cut and paste ERP, the one segment reserved for the sHKDS cut and paste ERP is released to the data set cut and paste ERP.

Using a cut and paste segment for reading a standard housekeeping data set

In one aspect of tape repositioning management in accordance with the present description, in response to loading a tape in a tape drive, mounting the tape linear tape file system (LTFS) is initiated including reading an index partition on the tape to extract metadata for mounting the tape LTFS, and prior to accessing a data area of the tape in response to any application access request, the tape is repositioned within a data partition to read a vHRTD (virtual High Resolution Tape Directory) recorded in an EOD (End of Data) portion such as an EOD data set, for example, of the data partition. The EOD portion is read to retrieve the vHRTD to facilitate application requested accesses to the tape. In one embodiment, repositioning and stopping the tape at the beginning of the data partition after reading the index partition containing metadata is bypassed.

Tape reposition management in a tape data storage drive

Aspects of the present disclosure relate to a method of writing a dataset to a tape, the dataset comprising a plurality of sub datasets, each sub dataset including a plurality of headers and a plurality of records. The method includes storing, in each header of each sub dataset, at least a portion of a record range indicator indicating a range of records included in the dataset.

Locating data within tape systems using sub dataset headers

An HRTD stored in the volatile memory of a tape drive is communicated for storage in an off-tape non-volatile memory prior to unloading a tape cartridge. In response to the tape cartridge being loaded into the tape drive, the HRTD is received from the off-tape non-volatile memory.

Non-volatile storage of high resolution tape directory

Repositioning to a beginning of an area of a tape medium to which a reposition request is directed can be completed. Reading, as a part of an error recovery procedure (ERP), between a first dataset of the area and an mdataset of the area, can be completed, where m is a number of datasets for which cut and paste multi segments are to be generated. Cut and paste segments for each of the datasets in a range from the first dataset and the mdataset can be generated. A subset of datasets within the range of the first dataset to the mdataset having readable dataset information table (DSIT) information can be determined. A determination can be made whether the target data position is included within the subset of datasets within the range of the first dataset to the mdataset by reading the DSIT information.

Repositioning using cut and paste segments

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.

Data storage beyond a threshold tape position

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.

Buffered writing of datasets and end longitudinal positions (end LPOSs) on a magnetic recording tape and validating the end LPOSs during reading of a later dataset thereafter

Growing community of inventors

Tokyo, Japan

Setsuko Masuda