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: Records or filemarks read from data segments are aggregated into at least one single data segment. The records and the filemarks are reorganized and restructured in the single data segment such that buffer utilization is improved.

Abstract: In one embodiment, a system includes a processor and logic integrated with and/or executable by the processor, the logic configured to: read data from a data storage medium, detect an error condition in data read from the data storage medium, determine how to allocate a ring buffer into a first portion and a second portion, the ring buffer being allocated for processing normal read and/or write requests, divide the ring buffer into the first portion and the second portion, 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, perform ERP on the data using the second portion of the ring buffer, determine that the ERP has been completed, and unify the ring buffer after the ERP is completed and allocate an entirety of the ring buffer for processing normal read and/or write requests.

Abstract: Data of a target capacity calculated by a nominal capacity of a tape medium minus a data capacity lost due to execution of backhitchless writing is written to the tape medium. In a tape drive, a command processing unit 41 receives a synchronization command, and a buffer management unit passes data in a buffer to a channel input-output unit. Upon completion of writing the data to the tape, a backhitch determination unit determines whether a mode information storage unit stores information indicating that a high data rate mode is on, whether data of a target capacity can be written to the tape, and whether the written data can be read at a target read data rate. An operation signal output unit issues a command to execute backhitch in case these conditions are not satisfied.

Abstract: In one embodiment, a system includes logic adapted to read a plurality of data sets from a medium one or more times; logic adapted to store portions of some of the data sets to a reserved data buffer when the portions are correctable using C1-error correction code (ECC); logic adapted to aggregate all stored portions for each of the complete data sets to form assembled data sets; logic adapted to determine whether C2-ECC is capable of correcting all errors in the assembled data sets, to correct any remaining errors in the assembled data sets, and to send the corrected data sets to a host when C2-ECC is capable of correcting all errors in the assembled data sets; and logic adapted to reread at least a first uncorrected data set from the medium using a different setting when an error in the first uncorrected data set is not correctable.

Abstract: In one embodiment, a system includes a processor configured to execute logic, the logic being configured to read a plurality of data sets, each data set including a plurality of portions which combine together to wholly form the data set, and reread at least a first uncorrected data set using a different setting in an error recovery procedure (ERP) when an error in the first uncorrected data set is not correctable using C2-ECC or an error in any portion of the first uncorrected data set is not correctable using C1-ECC. Other systems and methods for reading data from tape using a reconstructive ERP to reduce backhitches are presented according to more embodiments.

Abstract: A tape drive, tape drive recording system, and method are provided for improving tape speed selection during data transfer. The tape drive includes a buffer, a tape for recording the data to be temporarily stored in the buffer, and a read head. The tape drive further includes a reading controller that initially sets a tape speed such that a drive transfer rate matches a host transfer rate as closely as possible and that drives the tape at the tape speed. To address backhitching caused by one or more host transfer halts, the reading controller subsequently adjusts the tape speed such that the drive transfer rate is lower than the host transfer rate by recalculating the host transfer rate in consideration of the host transfer and the host transfer halt and setting the tape speed such that the drive transfer rate matches the recalculated host transfer rate as closely as possible.

Abstract: According to one embodiment, a method for reading data from a medium includes reading a data set from a medium 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 the 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, an apparatus includes logic configured to count each data set read and/or write access that used error recovery procedure (ERP) and each data set read and/or write access that did not use ERP, and logic configured to access subsequent data sets to read from and/or write to a data storage medium, wherein any subsequent data set read and/or write access that uses ERP is accessed using an initial ERP step characterized by a first speed of the data storage medium, and wherein the first speed is selected at least partially based on the count. Other systems and methods for ERP data access are described according to more embodiments.

Abstract: In one embodiment, a tape drive system includes a file system adapted for enabling sequential access to data on a tape medium, a file access controller adapted for managing the data, the file access controller including logic adapted for writing a file on the tape medium, logic adapted for writing a pointer of the written file in an index of the tape medium, wherein the pointer is managed by the file access controller, logic adapted for creating a high resolution tape directory (HRTD) including detailed location information of data on the tape medium, and logic adapted for storing the HRTD as part of end of data (EOD) of the index when a tape cartridge housing the tape medium is unloaded. Other systems, methods, and computer program products are described according to more embodiments.

Abstract: A tape drive capable of switching the transport speed of a tape medium among multilevel speeds calculates a data transfer rate from/to a host device, and selects an adjustment mode of the transport speed of the tape medium from a constant speed mode and a speed switch mode according to the calculated data transfer rate. The tape drive in the speed switch mode, pauses a data write or read operation to switch the transport speed of the tape medium while data is written at a first transport speed and when an available capacity of a buffer memory reaches a data volume to be received from the host device during switching of the transport speed and is read out at the first transport speed and when a data volume of a buffer memory reaches a data volume to be transmitted to the host device during switching of the transport speed.

Abstract: In one embodiment, a tape drive system includes a read channel, a write channel, logic adapted for accessing data sets using the read channel and/or the write channel, logic adapted for counting each data set access using the read channel that used error recovery procedure (ERP), logic adapted for counting each data set access using the read channel that did not use ERP, logic adapted for counting each data set access using the write channel that used ERP, logic adapted for counting each data set access using the write channel that did not use ERP, and logic adapted for accessing subsequent data sets using the read channel and/or the write channel, wherein any subsequent data set access that uses ERP is accessed using an initial ERP step characterized by a first tape speed, wherein the first tape speed is selected at least partially based on the counts.

Abstract: A tape recording apparatus in communication with a tape medium, and includes a head and a controlling unit to control the head to read and write data to the tape medium, wherein the controlling unit performs operations, comprising: determining an overwrite starting position by skipping data units whose beginning position cannot be determined until a data unit is reached having a beginning position that can be determined; and performing an overwrite operation at the overwrite starting position at the data unit whose beginning position can be determined.

Abstract: Records and filemarks read from data segments are aggregated into at least one single data segment. The records and the filemarks are reorganized and restructured in the single data segment such that buffer utilization is improved.

Abstract: According to one embodiment, a method includes writing, to a regular recording region of a tape medium after having written a first data accumulated in a buffer to a temporary recording region of the tape medium without an accompanying backhitch, a first data group that includes the first data that has any gaps between data eliminated, predicting a second volume of a second data, to be written in response to a command that is sent after the first data has been written to the regular recording region, judging whether the first volume exceeds a first threshold and whether or the second volume exceeds a second threshold, and writing the second data to the regular recording region without an accompanying backhitch when it has been judged that the first volume exceeds the first threshold and the second volume exceeds the second threshold.

Abstract: Methods, computer systems, and computer program products are provided for operating a tape drive comprising a tape medium with a plurality of record groups stored thereon. Access sequence for the plurality of record groups is provided. The tape medium is positioned for reading a record group in the access sequence before a seek command for the record group in the access sequence is received.

Abstract: A first data group in an access sequence is selected based on which data group in the data groups has a beginning closest to a current position of the tape medium. Those data groups located in specified regions of the tape medium are separated from other data groups located in alternative specified regions of the tape medium. The distance from the current position of the tape medium is set to be a logical distance value, determined by a calculation function, that is substituted for the physical distance value for the data groups that are located in the specified regions as compared with other data groups located in the alternative specified regions. A second data group in the access sequence is selected based on which remaining data group in the data groups has a beginning closest to an end of the first data group in the access sequence.

Abstract: Provided are a storage device, method, and program for controlling a tape speed to manage a tape drive buffer. A tape speed is increased from a current tape speed to a target tape speed on a predetermined speed-change timing to control the reading or writing of data between the buffer and the tape medium.

Abstract: A tape drive capable of switching the transport speed of a tape medium among multilevel speeds calculates a data transfer rate from/to a host device, and selects an adjustment mode of the transport speed of the tape medium from a constant speed mode and a speed switch mode according to the calculated data transfer rate. The tape drive in the speed switch mode, pauses a data write or read operation to switch the transport speed of the tape medium while data is written at a first transport speed and when an available capacity of a buffer memory reaches a data volume to be received from the host device during switching of the transport speed and is read out at the first transport speed and when a data volume of a buffer memory reaches a data volume to be transmitted to the host device during switching of the transport speed.

Abstract: The purpose of the present invention is to provide baked fatty or oily confectionery being crispy to the core but giving no burning feel, and a method for producing the same. The baked confectionery can be produced by preparing a fatty or oily confectionery composition containing a glucide, said glucide being selected from among isomaltulose, mannitol and reduced palatinose, and then baking the composition.