Abstract: The present invention provides a search method used to search for the reading order of a plurality of recording groups when the plurality of recording groups written on tape are continuously read by a tape drive which manages data on tape in recording units having a fixed data length for each recording. This search method includes the steps of: receiving information on a plurality of tape groups to be read; and sorting the plurality of recording groups to be read so the reading time is shortened. In the sorting step, the time required to sort the plurality of reading groups is reduced by combining two or more recording groups into a single object to be sorted in the sorting step when at least two or more contiguous recording groups have been assigned to the same region or are assigned across adjacent regions among the plurality of regions.

Abstract: An apparatus, computer readable medium device, and method for controlling transportation of a tape medium. A determination is made whether to execute a backhitch operation in response to writing a data set to tape from the buffer. If not, a determination is made whether a transaction size at which data is transferred from the buffer to the tape is less than a buffer size. If so, then a determination is made of a a new speed and whether a current speed is different from the determined new speed. If so, then a backhitch is initiated.

Abstract: Various embodiments for improving tape drive efficiency using a processor device are provided. In one embodiment, a method comprises aggregating one of records and filemarks, the aggregating restricted to being performed only on read operations, from a plurality of data segments into at least one single data segment, including sequentially aggregating the one of the records and filemarks into the at least one single data segment.

Abstract: The present invention provides a search method used to search for the reading order of a plurality of recording groups when the plurality of recording groups written on tape are continuously read by a tape drive which manages data on tape in recording units having a fixed data length for each recording. This search method includes the steps of: receiving information on a plurality of tape groups to be read; and sorting the plurality of recording groups to be read so the reading time is shortened. In the sorting step, the time required to sort the plurality of reading groups is reduced by combining two or more recording groups into a single object to be sorted in the sorting step when at least two or more contiguous recording groups have been assigned to the same region or are assigned across adjacent regions among the plurality of regions.

Abstract: An apparatus, computer readable medium device, and method for controlling transportation of a tape medium. A determination is made whether to execute a backhitch operation in response to writing a data set to tape from the buffer. If not, a determination is made whether a transaction size at which data is transferred from the buffer to the tape is less than a buffer size. If so, then a determination is made of a a new speed and whether a current speed is different from the determined new speed. If so, then a backhitch is initiated.

Abstract: Various embodiments for improving tape drive efficiency using a processor device are provided. In one embodiment, a method comprises aggregating one of records and filemarks, the aggregating restricted to being performed only on read operations, from a plurality of data segments into at least one single data segment, including sequentially aggregating the one of the records and filemarks into the at least one single data segment.

Abstract: In one embodiment, a tape drive includes a drive buffer, a processor, and logic integrated with and/or executable by the processor, the logic being configured to cause the processor to: receive a list including: user data segments recorded on tape media, wherein the user data segments are arranged in the list according to a predetermined order, and information associated with each user data segment, wherein the information includes a description of a physical location of each of the user data segments on the tape media. The logic is further configured to cause the processor to locate each of the user data segments on the tape media according to the order in the list, read each of the user data segments from the tape media according to the order in the list, and write each of the user data segments to a buffer according to the order in the list.

Abstract: In one embodiment, a tape drive includes a reserved data buffer and logic integrated with and/or executable by a processor. The logic is configured to read a data set from a medium and store a first portion of the data set to the reserved data buffer in response to a determination that the first portion of the data set is correctable using C2 error correction code (ECC). The logic is also configured to replace any stored row of a non-C2-correctable portion of the data set stored to the reserved data buffer with a corresponding row of the data set read from the medium in response to a determination that the stored row of the non-C2-correctable portion of the data set has an equal amount or more C1-correctable error therein than the corresponding row of the data set read from the medium.

Abstract: An apparatus, computer readable medium device, and method for controlling transportation of a tape medium. A determination is made whether to execute a backhitch operation in response to writing a data set to tape from the buffer. If not, a determination is made whether a transaction size at which data is transferred from the buffer to the tape is less than a buffer size. If so, then a determination is made of a a new speed and whether a current speed is different from the determined new speed. If so, then a backhitch is initiated.

Abstract: Records or filemarks read from data segments are aggregated into at least one single data segment. The records and the filemarks are padded at an end of the one single data segment, such that the padding of the end of the one single data segment is less than padding of the one of the records and filemarks in the plurality of data segments.

Abstract: In one embodiment, a method is provided for adapting a host transfer rate between a host and a tape drive to a medium transfer rate between the tape drive and a tape. A data compression rate of untransferred data in a buffer of a tape drive is measured. A change in a future host transfer rate is predicated based on the measured compression rate. A host transfer rate between a host and the tape drive is adapted to a medium transfer rate between the tape drive and a tape, based on the predicted change.

Abstract: In one embodiment, a method for dynamically allocating a memory includes dividing a memory into a first portion and a second portion in response to detecting an error condition when reading data from a data storage medium. The first portion is allocated for processing normal read and/or write requests. The second portion is allocated for processing error recovery procedure (ERP) requests. In another embodiment, a computer program product for dynamically allocating a memory includes a computer readable storage medium having program code embodied therewith. The program code is readable/executable by a processor to divide, by the processor, a memory into a first portion and a second portion in response to detecting an error condition when reading data from a data storage medium. The first portion is allocated for processing normal read and/or write requests. The second portion is allocated for processing ERP requests.

Abstract: In one general embodiment, a method includes receiving a request for a write operation to be performed in a tape drive; determining a capacity margin ratio of the tape drive; determining an optimum a write procedure based at least in part on the capacity margin ratio; and invoking the optimum write procedure in response to determining the optimum write procedure. The optimum write procedure is selected from the group consisting of: a backhitch write procedure, a same wrap backhitchless flush (SWBF) write procedure, and a recursively accumulating backhitchless flush (RABF) write procedure. Systems and computer program products configured to perform similar techniques are also disclosed.

Abstract: In one embodiment, a method for assembling data from a medium includes reading a data set from the medium repeatedly using different settings until either: a reconstructed data set is obtained, or a maximum number of rereads has been reached, the data set including a plurality of sub data sets, each sub data set having a plurality of rows, and after each reread of the data set, good rows of data are stored to iteratively construct a good data set from a plurality of good rows as determined by C1 and/or C2 error correction code (ECC).

Abstract: According to one embodiment, a method for reading data includes reading a data set repeatedly using different settings until either: a reconstructed data set is sent to a host and/or stored, or a maximum number of rereads has been reached, after each reading of the data set, storing each row to a reserved data buffer that has no errors or errors in the row are correctable using C1-error correction code (ECC) unless a matching row already exists in the reserved data buffer that has fewer corrected errors therein, assembling the data set from the rows stored in the reserved data buffer to form an assembled data set, correcting any remaining errors in the assembled data set using C2-ECC to form the reconstructed data set, and sending the reconstructed data set to the host and/or storing the reconstructed data set.

Abstract: In one embodiment, a system for dynamically allocating a ring buffer includes a processor and logic integrated with and/or executable by the processor, the logic being configured to divide a ring buffer into a first portion and a second portion after detecting an error condition in data read from a data storage medium, wherein the first portion is allocated for processing normal read and/or write requests, and wherein the second portion is allocated for processing error recovery procedure (ERP) requests. In another embodiment, a method for dynamically allocating a ring buffer includes dividing a ring buffer into a first portion and a second portion after detecting an error condition in data read from a data storage medium, wherein the first portion is allocated for processing normal read and/or write requests, and wherein the second portion is allocated for processing ERP requests.

Abstract: An apparatus, computer readable medium device, and method for controlling transportation of a tape medium. A determination is made whether to execute a backhitch operation in response to writing a data set to tape from the buffer. If not, a determination is made whether a transaction size at which data is transferred from the buffer to the tape is less than a buffer size. If so, then a determination is made of a a new speed and whether a current speed is different from the determined new speed. If so, then a backhitch is initiated.

Abstract: Data is recorded such that the positions of data will be aligned in a traveling direction and a width direction of the storage medium. The medium travels in the traveling direction from a first to a second position as a certain wrap of a group of plural files in a first physical range between the first and the second positions. A head shifts from the certain wrap to another wrap in the width direction of the medium. The medium travels in the traveling direction from a third to a fourth position as the other wrap of a group of plural files in a second physical range between the third and the fourth positions. The plural files in groups on the certain wrap and the other wrap may be written in reverse order to each other after being once stored in a buffer.

Abstract: Data is recorded such that the positions of data will be aligned in a traveling direction and a width direction of the storage medium. The medium travels in the traveling direction from a first to a second position as a certain wrap of a group of plural files in a first physical range between the first and the second positions. A head shifts from the certain wrap to another wrap in the width direction of the medium. The medium travels in the traveling direction from a third to a fourth position as the other wrap of a group of plural files in a second physical range between the third and the fourth positions. The plural files in groups on the certain wrap and the other wrap may be written in reverse order to each other after being once stored in a buffer.

Abstract: In one embodiment, an apparatus for reading data from a data storage medium includes a processor and logic integrated with and/or executable by the processor, the logic being configured to: read data from a data storage medium, the data including a plurality of data sets, determine that an error condition is detected for a data set read from the data storage medium, determine whether the data set was read from the data storage medium using multiple cut and paste (C/P) error recovery procedure (ERP) (C/P ERP Multi), and when the data set was read from the data storage medium using C/P ERP Multi: continue reading data from the data storage medium normally when the detected error condition has been overcome using C/P ERP Multi; otherwise, continue using C/P ERP Multi to read data from the data storage medium until the error condition is overcome.