Patent application number | Description | Published |
20090303633 | Same Wrap Backhitchless Write Method to Encode Data on a Tape Storage Medium - A method to write information to a tape storage medium by disposing a tape storage medium in a tape drive apparatus comprising a write head. The method moves the tape storage medium in a first direction, writes data from a buffer to the tape storage medium, and thereby empties the buffer while the tape storage medium is moving in the first direction. The method determines, while the tape storage medium is moving in the first direction, whether to enable a backhitchless write wherein the tape storage medium is not stopped and moved in a second and opposition direction, prior to writing new data to the tape storage medium. By not stopping the movement of the tape storage medium, and by not moving the tape storage medium in a reverse direction to reposition the write head, the method eliminates the time overhead required to stop the tape and reposition the tape head. Applicants' method achieves this time efficiency without adverse impact to the nominal storage capacity of the tape information medium. | 12-10-2009 |
20100007978 | DETECTION OF DEFECTIVE TAPE DRIVE BY AGGREGATING READ ERROR STATISTICS - A plurality of tape drives writes a plurality of indicators corresponding to a plurality of data units on a tape, wherein an indicator indicates which tape drive of the plurality of tape drives has written a corresponding data unit on the tape. Each of the plurality of tape drives generates an extent of read errors, in response to reading the plurality of data units written on the tape. The extent of read errors generated by each of the plurality of tape drives are aggregated at a computational device coupled to the plurality of tape drives. A determination is made at the computational device of a defective tape drive of the plurality of tape drives from the aggregated extent of read errors. | 01-14-2010 |
20100118430 | METHOD AND SYSTEM FOR IMPROVING DATA ACCESS TIME - A computer implemented method of writing data to a linear tape is provided and includes, of the data to be written to the linear tape, distinguishing between data and meta-information, writing both the distinguished meta-information and undistinguished meta-information to a data area of the linear tape and the distinguished meta-information to a reserved area at a leading end of the linear tape, and retaining information reflective of the meta-information and a location thereof in a specified position of the reserved area. | 05-13-2010 |
20100302667 | DETECTION OF DEFECTIVE TAPE DRIVE BY AGGREGATING READ ERROR STATISTICS - A plurality of tape drives writes a plurality of indicators corresponding to a plurality of data units on a tape, wherein an indicator indicates which tape drive of the plurality of tape drives has written a corresponding data unit on the tape. Each of the plurality of tape drives generates an extent of read errors, in response to reading the plurality of data units written on the tape. The extent of read errors generated by each of the plurality of tape drives are aggregated at a computational device coupled to the plurality of tape drives. A determination is made at the computational device of a defective tape drive of the plurality of tape drives from the aggregated extent of read errors. | 12-02-2010 |
20110222379 | METHOD FOR CONTROLLING OVERWRITING OF DATA BY TAPE RECORDING APPARATUS , PROGRAM FOR CONTROLLING OVERWRITING , AND TAPE RECORDING APPARATUS - A data-overwriting technique that facilitates determining whether data is new or old, when reading thereof. A tape recording apparatus includes: a receiving unit for receiving information on overwrite starting position and an overwrite request; a trying unit for trying to determine a beginning position of a data unit based on the information on an overwrite starting position, wherein the data unit is a unit of writing data recorded on a tape medium; an overwrite executing unit for executing overwriting from the determined overwrite starting position in response to a success of the determination by the trying unit; and a type judging unit for judging whether the data unit that is recorded at the overwrite starting position is a null data unit or not in response to a failure of the determination by the trying unit. The trying unit responds to judgment that the data unit is the null data unit by trying to determine a beginning of a data unit following the data unit as the overwrite starting position. | 09-15-2011 |
20120079185 | TAPE STORAGE SYSTEM INCLUDING MULTIPLE TAPE STORAGE APPARATUSES - A tape storage system according to one embodiment includes two or more tape storage apparatuses each having a buffer divided in fixed-length segments, and being connectable to a host, where a first of the tape storage apparatuses is configured to receive multiple data clusters and a synchronization request from a host, and, when one of the segments of the buffer is accumulated and filled with the data, to write the accumulated data onto a tape. A second of the tape storage apparatuses is connected to the first tape storage apparatus, the second tape storage apparatus being configured to receive the multiple data clusters sent from the host via the first tape storage apparatus, and being configured to write a predetermined number of data clusters accumulated in the segments thereof onto a second tape at a timing corresponding to the synchronization request. | 03-29-2012 |
20120212848 | OVERWRITE CONTROL METHOD FOR DATA IN TAPE RECORDING APPARATUS, AND TAPE RECORDING APPARATUS - A data-overwriting technique that facilitates determining whether data is new or old. A tape recording apparatus includes: a receiving unit for receiving information on overwrite starting position and an overwrite request; a trying unit for trying to determine a beginning position of a data unit; an overwrite executing unit for executing overwriting from the determined overwrite starting position in response to a success of the determination by the trying unit; and a type judging unit for judging whether the data unit that is recorded at the overwrite starting position is a null data unit or not in response to a failure of the determination by the trying unit. The trying unit responds to judgment that the data unit is the null data unit by determining a beginning of a data unit following the data unit as the overwrite starting position. | 08-23-2012 |
Patent application number | Description | Published |
20090190893 | OPTICAL PULSE COMPRESSOR - Optical pulse compressor having a chirp unit including a normal dispersion fiber that provides a positive chirp to an input pulse and having a dispersion compensator including an anomalous fiber is provided. The nonlinear coefficient and the absolute value of the second-order group-velocity dispersion of the anomalous fiber that forms the dispersion compensator is set such that a soliton order becomes one or more, and the fiber length of the anomalous dispersion fiber is made to be equal to or smaller than a length required for optical soliton formation. | 07-30-2009 |
20090213880 | PULSE LASER APPARATUS, TERAHERTZ MEASURING APPARATUS, AND TERAHERTZ TOMOGRAPHIC APPARATUS - A pulse laser apparatus includes a laser configured to generate a pulse of a laser beam, a fiber amplifier, and a pulse compressor. The fiber amplifier includes a rare-earth doped fiber that exhibits normal dispersion at a wavelength of the laser beam generated from the laser. The pulse laser apparatus further includes a unit configured to give a loss to energy portions in a wavelength region corresponding to a zero-dispersion wavelength of the rare-earth doped fiber and/or a wavelength region longer than the zero-dispersion wavelength within a wavelength spectrum of the laser beam having been chirped in the fiber amplifier. | 08-27-2009 |
20100084570 | TERAHERTZ WAVE GENERATOR - Provided is a terahertz wave generator that improves efficiency of generating a terahertz wave. The terahertz wave generator includes a generating layer for generating the terahertz wave, a waveguide layer for propagating excitation light entering the generating layer and a terahertz wave generated by the excitation light entering the generating layer, and a first confinement layer for confining in the waveguide layer the excitation light propagating in the waveguide layer and the terahertz wave propagating in the waveguide layer. The generating layer, the waveguide layer, and the first confinement layer are laminated in the stated order. | 04-08-2010 |
20100288928 | APPARATUS AND METHOD FOR MEASURING TERAHERTZ WAVE - An apparatus for measuring a terahertz wave includes a dispersing section | 11-18-2010 |
20110210252 | PULSE LASER APPARATUS, TERAHERTZ MEASURING APPARATUS, AND TERAHERTZ TOMOGRAPHIC APPARATUS - A pulse laser apparatus includes a laser configured to generate a pulse of a laser beam, a fiber amplifier, and a pulse compressor. The fiber amplifier includes a rare-earth doped fiber that exhibits normal dispersion at a wavelength of the laser beam generated from the laser. The pulse laser apparatus further includes a unit configured to give a loss to energy portions in a wavelength region corresponding to a zero-dispersion wavelength of the rare-earth doped fiber and/or a wavelength region longer than the zero-dispersion wavelength within a wavelength spectrum of the laser beam having been chirped in the fiber amplifier. | 09-01-2011 |
20120177332 | Optical Pulse Compressor - Optical pulse compensator having a chirp unit including a normal dispersion fiber that provides a positive chirp to an input pulse and having a dispersion compensator including an anomalous fiber is provided. The nonlinear coefficient and the absolute value of the second-order group-velocity dispersion of the anomalous fiber that forms the dispersion compensator is set such that a soliton order becomes one or more, and the fiber length of the anomalous dispersion fiber is made to be equal to or smaller than a length required for optical soliton formation. | 07-12-2012 |
Patent application number | Description | Published |
20090296267 | APPARATUS AND METHOD FOR WRITING DATA ONTO TAPE MEDIUM - In a controller of a tape drive, when a command processing unit receives a Write FM | 12-03-2009 |
20090296268 | SYSTEM AND METHOD FOR CONTROLLING TRAVELING OF TAPE - A system and method for controlling the traveling of a tape is provided. The system and method include passing data in a buffer to a channel input/output unit for writing the data to a tape. Once the data is written to the tape, a determining unit determines whether or not to perform backhitchless writing. If backhitchless writing is to be performed, then a speed determining unit determines a tape speed, where the time of data transfer from a host to the buffer is less than the time of data writing from the buffer to the tape. Thereafter, an operation signal output unit instructs a motor driver to change the speed of the tape to the determined tape speed after a backhitch is performed is a speculative FM. | 12-03-2009 |
20100053801 | DEVICE AND METHOD FOR PROCESSING DATA RECORDED ON A TAPE MEDIUM - A device and method are disclosed for processing data recorded on a tape medium. The device comprises a first control part controls a read head to read specific data recorded in a first area among data recorded in a first format on the tape medium. The device further comprises a second control part that controls a write head to write the specific data in a second area different from the first area of the tape medium and to write the specific data in a second format in a third area different from the second area of the tape medium. Moreover, the device may comprise a recording part for recording specific information that specifies a read position of other data among data recorded in the first format on the tape medium. | 03-04-2010 |
20100095029 | TAPE DRIVE, TAPE DRIVE RECORDING SYSTEM, AND METHOD FOR SELECTING IMPROVED TAPE SPEED IN RESPONSE TO INTERMITTENT READ REQUESTS - A tape drive, tape drive recording system, and method are provided for improving tape speed selection during data transfer. The tape drive comprises a buffer, a tape for recording the data to be temporarily stored in the buffer, and a read head. The tape drive further comprises 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. | 04-15-2010 |
20120162807 | METHOD AND SYSTEM FOR OPERATING A TAPE DRIVE - 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. | 06-28-2012 |
20120290784 | TAPE DRIVE, TAPE DRIVE RECORDING SYSTEM, AND METHOD FOR SELECTING IMPROVED TAPE SPEED IN RESPONSE TO INTERMITTENT READ REQUESTS - 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. | 11-15-2012 |
20120293887 | APPARATUS AND METHOD FOR CONTROLLING DATA WRITING TO A TAPE MEDIUM - 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 | 11-22-2012 |
Patent application number | Description | Published |
20080285166 | METHOD FOR CONTROLLING DRIVE OF RECORDING MEDIUM - A method of controlling a drive of a recording medium according to one embodiment includes receiving data from a host, and writing the data to the recording medium. A difference in volume between the data at the time of being received from the host and the data at the time of being written to the recording medium is detected. An adjustment is made to at least one of a first transfer rate with the recording medium, and a second transfer rate with the host, based on the difference. | 11-20-2008 |
20080294954 | SYSTEM, METHOD AND PROGRAM FOR PROCESSING READ ERROR - A system for processing a data read error from a tape medium in one embodiment includes a reading section for reading data in data units from a tape medium; a reading control section for controlling said reading section to read data, and on condition that if an error occurs in reading one of said data units, the data unit where the error occurs is considered an error data unit and the reading control section issues an instruction to skip the error data unit and read the next readable data unit immediately after the error data unit; a computation section for computing a number of records and a number of boundary marks included in the error data unit where said error occurs from information about the records and boundary marks included in the data unit preceding the error data unit that is read immediately before said error occurs, and information about the records and boundary marks included in the data unit next to said error data unit, the boundary marks indicating the boundary of a record block; and a communication section for outputting the number information about said computed number of records and said computed number of boundary marks. | 11-27-2008 |
20080304174 | OPTIMIZING TAPE SPEED FOR A SYNC OPERATION - Provided are techniques for determining a tape speed for a next sync operation. A sync command is received. An average transaction size and an average host transfer rate of a set of previous sync operations are calculated. The tape speed for the next sync operation is determined using the average transaction size, the average host transfer rate, and a backhitch time. Data is written to a tape cartridge using the determined tape speed. | 12-11-2008 |
20090063763 | CONTROLLING WRITING TO MAGNETIC TAPE - A method for controlling writing for a tape recorder that is connected to a host and sequentially records, as a transaction, a plurality of records that are transferred from the host and stored in a buffer is provided, including receiving a synchronous command for a first transaction from the host; in response to the synchronous command, sequentially writing the plurality of records stored in the buffer to a tape as the first transaction; receiving the size of a second transaction following the first transaction from the host; calculating time for a backhitch associated with an operation of the synchronous command for the first transaction on the basis of the size; and performing the backhitch on the basis of the time for the backhitch. | 03-05-2009 |
20130258516 | ERROR RECOVERY PROCEDURE (ERP) USING ESTIMATED BEST SETTING IN FIRST RUN - 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. | 10-03-2013 |
20130275666 | WRITE PROCEDURE USING ESTIMATED BEST SETTING IN FIRST RUN - In one general embodiment, a tape drive system includes: a read channel; a write channel; logic configured to receiving a request for a write operation to be performed in a tape drive; logic configured to determine an optimum a write procedure in response to receiving the request, the determining being based on expected writing times of each of a plurality of write procedures and an expected transaction size of a next write operation; and logic configured to invoke the determined optimum write procedure in response to determining the optimum write procedure. | 10-17-2013 |
20130275667 | WRITE PROCEDURE USING ESTIMATED BEST SETTING IN FIRST RUN - In one general embodiment, a method includes receiving a request for a write operation to be performed in a tape drive, determining an expected transaction size of a next write operation, comparing the expected transaction size of the next write operation to each of a first transaction size threshold and a second transaction size threshold in response to receiving the request, determining an optimum a write procedure based at least in part on the comparison, and invoking the optimum write procedure in response to determining the optimum write procedure, wherein the first transaction size threshold is greater than the second transaction size threshold, and wherein 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. | 10-17-2013 |
20140108720 | HIGH RESOLUTION TAPE DIRECTORY (HRTD) STORED AT END OF DATA IN AN INDEX PARTITION - 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. | 04-17-2014 |
20140126079 | ERROR RECOVERY PROCEDURE (ERP) USING ESTIMATED BEST SETTING IN FIRST RUN - 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. | 05-08-2014 |
20140136918 | RECONSTRUCTIVE ERROR RECOVERY PROCEDURE (ERP) USING RESERVED BUFFER - 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. | 05-15-2014 |
20140136919 | RECONSTRUCTIVE ERROR RECOVERY PROCEDURE (ERP) FOR MULTIPLE DATA SETS USING RESERVED BUFFER - 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. | 05-15-2014 |
20140189460 | RECONSTRUCTIVE ERROR RECOVERY PROCEDURE (ERP) FOR MULTIPLE DATA SETS USING RESERVED BUFFER - 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. | 07-03-2014 |
20150026510 | DYNAMIC BUFFER SIZE SWITCHING FOR BURST ERRORS ENCOUNTERED WHILE READING A MAGNETIC TAPE - 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. | 01-22-2015 |
20150058504 | DYNAMICALLY CHANGING A BUFFER FLUSH THRESHOLD OF A TAPE DRIVE BASED ON HISTORICAL TRANSACTION SIZE - According to one embodiment, a method for dynamically changing a buffer threshold in a tape drive includes determining that a drive buffer is emptied of data, calculating a write size indicating an amount of data from a transaction size left to be written to a tape prior to a next anticipated sync command, setting a buffer threshold that triggers a back hitch to a smaller value when the transaction size is less than a buffer size, setting the buffer threshold to the smaller value when an absolute difference between the transaction size and the write size is greater than or equal to the buffer size, and setting the buffer threshold to a larger value when the transaction size is not less than the buffer size and/or the absolute difference between the transaction size and the write size is less than the buffer size. | 02-26-2015 |
20150113216 | REDUCING ELAPSED TIME TO ACCESS DATA FROM A STORAGE MEDIUM DURING A RECALL OPERATION - 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. | 04-23-2015 |
Patent application number | Description | Published |
20110116185 | TRANSPORT SPEED ADJUSTMENT DEVICE, TRANSPORT SPEED ADJUSTMENT METHOD AND TRANSPORT SPEED ADJUSTMENT PROGRAM FOR ADJUSTING TRANSPORT SPEED OF TAPE MEDIUM - 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. | 05-19-2011 |
20120154946 | METHOD AND SYSTEM FOR DETERMINING ACCESS SEQUENCE OF DATA STORED ON A TAPE MEDIUM - Methods, computer systems, and computer program products are provided for determining an access sequence of a plurality of data groups stored on a tape medium. A first data group in the access sequence is selected based on which data group in the plurality of data groups has a beginning closest to a current position of the tape medium. A second data group in the access sequence is selected based on which remaining data group in the plurality of data groups has a beginning closest to an end of the first data group in the access sequence. | 06-21-2012 |
20120206831 | TRANSPORT SPEED ADJUSTMENT DEVICE, TRANSPORT SPEED ADJUSTMENT METHOD AND TRANSPORT SPEED ADJUSTMENT PROGRAM FOR ADJUSTING TRANSPORT SPEED OF TAPE MEDIUM - 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. | 08-16-2012 |
20120250176 | METHOD AND SYSTEM FOR DETERMINING ACCESS SEQUENCE OF DATA STORED ON A TAPE MEDIUM - For determining an access sequence of a plurality of data groups stored on a tape medium, a first data group in the access sequence is selected based on which data group in the plurality of data groups has a beginning closest to a current position of the tape medium. A second data group in the access sequence is selected based on which remaining data group in the plurality of data groups has a beginning closest to an end of the first data group in the access sequence. | 10-04-2012 |
20140043710 | REDUCING TOTAL SEEK TIME FOR DETERMINING AN ACCESS SEQUENCE OF DATA STORED ON A TAPE MEDIUM - 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. | 02-13-2014 |
20140063634 | TAPE DRIVE BUFFER UTILIZATION - 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. | 03-06-2014 |
20140247515 | TAPE DRIVE BUFFER UTILIZATION - 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. | 09-04-2014 |
20150055442 | REDUCING TOTAL SEEK TIME FOR DETERMINING AN ACCESS SEQUENCE OF DATA STORED ON A TAPE MEDIUM - A first data group in an access sequence is selected. 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. The logical distance value is then determined by multiplying a coefficient based on a physical positioning of each of the data groups in the tape medium, and a percentage of those of the plurality of data groups that have already been selected as the first data group and the second data group. | 02-26-2015 |
Patent application number | Description | Published |
20130155540 | TAPE BUFFER USED TO REDUCE TAPE BACKHITCHES DURING WRITING OPERATIONS - 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. | 06-20-2013 |
20130159643 | DETECTING TAMPERING OF DATA DURING MEDIA MIGRATION, AND STORAGE DEVICE - A method for detecting at a migration destination medium a change in data during media migration between write once read many (WORM) media according to one embodiment includes writing data for WORM from a migration source medium to the migration destination medium; holding an identifier (ID) of the source medium in a non-user storage area in the destination medium; and holding information indicating a feature of the data in the non-user storage area. | 06-20-2013 |
20130163397 | OVERWRITE CONTROL FOR DATA IN TAPE RECORDING APPARATUS - 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. | 06-27-2013 |
20140022665 | CONTROLLING A TAPE SPEED TO MANAGE A TAPE DRIVE BUFFER - 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. | 01-23-2014 |
20140268399 | READING ORDER SEARCH METHOD AND PROGRAM FOR RECORDING GROUPS ON TAPE - 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. | 09-18-2014 |
20150036237 | CONTROLLING A TAPE SPEED TO MANAGE A TAPE DRIVE BUFFER - 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. | 02-05-2015 |
20150058645 | REDUCTION OF POWER CONSUMPTION OF A BUFFER IN A TAPE DRIVE - A method of reducing power consumption of a buffer for cache in a tape drive connected to a host in a communicable manner, according to one embodiment, includes detecting a transfer rate of data from the host or to the host, and determining a writing or reading rate of data to or from a tape based on the data transfer rate. A determination is made as to whether predetermined conditions including the data transfer rate, the data writing or reading rate, and a capacity of a buffer are satisfied, where the buffer includes at least two buffer areas. At least one of the buffer areas is selected when the predetermined conditions are satisfied. The selected buffer area is switched to a power saving mode. | 02-26-2015 |