Abstract: Embodiments of the present invention provide methods, systems, and computer program products for compensating for loss of current through shorted tunneling magnetoresistance (TMR) sensors. In one embodiment, for a magnetic head having multiple TMR read sensors, a first voltage limit is set for most parts and a second voltage limit is set for all of the parts. A number of TMR read sensors which are allowed to function between the first and the second voltage limits is determined using a probability algorithm, which determines the probability that the application of the second voltage limit will result in a dielectric breakdown within an expected lifetime of a drive is below a threshold value. For the number of TMR read sensors which are allowed to function at voltages between the first and second voltage limits, a determined subset of those sensors are then allowed to function at the second voltage limit.

Abstract: A method, according to one embodiment, includes writing a plurality of shingled tracks using an array of writers, determining first and second positions of an array of readers relative to the shingled tracks, the first and second positions being above and/or beyond track edges of the shingled tracks, repositioning the array of readers to various locations between the first and second positions and reading data from the shingled tracks, determining a read offset point where read performance is about the highest during the reading performed when repositioning the array of readers between the first and second positions, and computing, using the read offset point, data describing a lateral writing position to use during writing such that shingled tracks are written in a location specified by a format. Other systems, methods, and computer program products are described in additional embodiments.

Abstract: A method according to one embodiment includes gathering information about how an array of writers write and/or are expected to write to a magnetic medium during shingled recording, and computing, using the gathered information, data describing a lateral writing position to use during writing such that shingled track edges are aligned according to a format. A method according to another embodiment includes obtaining a lateral offset from a nominal writing position, and applying the lateral offset for repositioning a writing position of an array of writers relative to a nominal writing position during writing in a first direction. A product according to one embodiment includes a magnetic recording medium; and data indicative of whether a lateral writing position offset was used while writing.

Abstract: Embodiments of the present invention provide methods, systems, and computer program products for compensating for loss of current through shorted tunneling magnetoresistance (TMR) sensors. In one embodiment, for a magnetic head having multiple TMR read sensors, a first voltage limit is set for most parts and a second voltage limit is set for all of the parts. A number of TMR read sensors which are allowed to function between the first and the second voltage limits is determined using a probability algorithm, which determines the probability that the application of the second voltage limit will result in a dielectric breakdown within an expected lifetime of a drive is below a threshold value. For the number of TMR read sensors which are allowed to function at voltages between the first and second voltage limits, a determined subset of those sensors are then allowed to function at the second voltage limit.

Abstract: A computer-implemented method includes: determining a reading performance of a head positioned at a commanded lateral reading location based on one or more metrics; adjusting a lateral reading location of the head relative to a medium by moving the head in a lateral direction away from the commanded lateral reading location to an adjusted lateral reading location; determining a reading performance of the head after the adjusting; comparing the reading performance after the adjusting to the reading performance before the adjusting for determining whether the reading performance has improved; and selecting an optimal lateral reading location based on the comparing. The one or more metrics are selected from a group consisting of C1 error correction rate, and C2 error correction rate. Corresponding systems and computer program products are also disclosed.

Abstract: In one embodiment, a method includes determining a reading performance based on one or more metrics, adjusting a commanded lateral reading location of a head relative to a medium, determining the reading performance after the adjusting, comparing the reading performance after the adjusting relative to the reading performance before the adjusting for determining whether the reading performance has improved, and selecting a commanded lateral reading location based on the comparing. In another embodiment, a controller is configured to perform the foregoing method. In yet another embodiment, a computer program product includes a computer readable storage medium having program instructions embodied therewith, the program instructions readable and/or executable by a controller configured to perform the foregoing method.

Abstract: A method according to one embodiment includes monitoring a plurality of parameters relating to operation of a tape drive to collect data from the operation of the tape drive. A specification of one or more of the parameters to log during one or more collection windows is received. At least some of the data collected from the operation of the tape drive is logged to a memory during the one or more collection windows, where the at least some of the data collected is stored in a plurality of fields. The method further includes dynamically overlaying one or more of the fields with data corresponding to the one or more specified parameters.

Abstract: Described herein are embodiments for utilizing stored write environment conditions for read error recovery. A tape drive measures read environment conditions as a result of receiving a read command to read data from a portion of tape and compares the read environment conditions to the write environment conditions stored for that portion of tape. If the read environment conditions are not within the predetermined range of the write environment conditions, then the handling of the tape is altered to improve read element placement on the tape by accounting for expansion and contraction of the tape based on the stored write environment conditions. The handling of the tape is altered by at least one of increasing or decreasing the tension of the tape, offsetting the tape head up or down laterally with respect to the tape, and slowing down the movement of tape across the tape head.

Abstract: Described herein are embodiments for utilizing stored write environment conditions for read error recovery. A tape drive measures read environment conditions as a result of receiving a read command to read data from a portion of tape and compares the read environment conditions to the write environment conditions stored for that portion of tape. If the read environment conditions are not within the predetermined range of the write environment conditions, then the handling of the tape is altered to improve read element placement on the tape by accounting for expansion and contraction of the tape based on the stored write environment conditions. The handling of the tape is altered by at least one of increasing or decreasing the tension of the tape, offsetting the tape head up or down laterally with respect to the tape, and slowing down the movement of tape across the tape head.

Abstract: In one embodiment, a method includes determining a reading performance based on one or more metrics, adjusting a commanded lateral reading location of a head relative to a medium, determining the reading performance after the adjusting, comparing the reading performance after the adjusting relative to the reading performance before the adjusting for determining whether the reading performance has improved, and selecting a commanded lateral reading location based on the comparing. In another embodiment, a controller is configured to perform the foregoing method. In yet another embodiment, a computer program product includes a computer readable storage medium having program instructions embodied therewith, the program instructions readable and/or executable by a controller configured to perform the foregoing method.

Abstract: Described are embodiments of an invention for storing write environment conditions of a tape cartridge. A tape drive measures and stores the write environment conditions for a portion of tape as a result of receiving a write command to write data to the same portion of tape. In one embodiment, the write environment conditions are measured and stored to the tape cartridge each time a write command is received such that each portion of tape written has corresponding stored write environment conditions. The write environment conditions include temperature and relative humidity in one embodiment. The stored write environment conditions for each portion of tape written creates a historical log of the environment conditions that the tape was written within. The historical log can provide information to a manufacturer or user regarding the environmental conditions the user operates their tape drive within and provides information to assist with failure analysis.

Abstract: Magnetoresistive (MR) bias is dynamically controlled in a tape drive using a processor device. Median tape head amplitude is monitored during a calibration operation, as measured across all tracks of the tape head, against predetermined thresholds of the tape drive for determining if the median tape head amplitude is below the threshold value. Upon determining the median tape head amplitude is below the threshold value during the calibration operation, a reference MR bias and a MR bias range is dynamically adjusted, during the calibration operation, for increasing the median tape head amplitude.

Abstract: A method according to one embodiment includes monitoring a plurality of parameters relating to operation of a tape drive to collect data from the operation of the tape drive. A specification of one or more of the parameters to log during one or more collection windows is received. At least some of the data collected from the operation of the tape drive is logged to a memory during the one or more collection windows, where the at least some of the data collected is stored in a plurality of fields. The method further includes dynamically overlaying one or more of the fields with data corresponding to the one or more specified parameters.

Abstract: Described herein are embodiments for utilizing stored write environment conditions for read error recovery. A tape drive measures read environment conditions as a result of receiving a read command to read data from a portion of tape and compares the read environment conditions to the write environment conditions stored for that portion of tape. If the read environment conditions are not within the predetermined range of the write environment conditions, then the handling of the tape is altered to improve read element placement on the tape by accounting for expansion and contraction of the tape based on the stored write environment conditions. The handling of the tape is altered by at least one of increasing or decreasing the tension of the tape, offsetting the tape head up or down laterally with respect to the tape, and slowing down the movement of tape across the tape head.

Abstract: In one embodiment, a method includes making a determination whether to modify a cleaning cycle, e.g., of a tape drive, based at least in part on at least one of: an age of one or more tapes, a type of one or more tapes, and an identity of a vendor of one or more tapes. A selection and/or modification of a timing of a cleaning operation is made based on the determination.

Abstract: According to one embodiment, a method includes monitoring a plurality of parameters relating to operation of a tape drive to collect data from the operation of the tape drive, receiving a specification of one or more user-specified parameters to log during one or more collection windows, wherein the one or more user-specified parameters are specified from the plurality of parameters, logging at least some of the data collected from the operation of the tape drive to a memory during the one or more collection windows, wherein the at least some of the data collected is stored in a tape map comprising a plurality of fields, the plurality of fields including at least one histogram field, at least one per-channel field, and at least one per-channel indicator field, and dynamically overlaying one or more fields from the plurality of fields with data collected from the one or more user-specified parameters.

Abstract: According to one embodiment, a system includes a tape drive for reading from and/or writing to magnetic tape media, the tape drive having a memory and logic adapted for: monitoring parameters relating to operation of the tape drive to collect data from the operation of the tape drive, receiving a specification of an owner interface comprising a source of specifiable parameters, receiving one or more user-specified parameters from the owner interface to log during a collection window, logging at least some of the data collected from the operation of the tape drive to the memory during the collection window, wherein the at least some of the data collected is stored in a tape map including a plurality of fields, and dynamically overlaying one or more fields from the plurality of fields with data collected from the one or more user-specified parameters. The plurality of fields includes at least one histogram field, at least one per-channel field, and at least one per-channel indicator field.

Abstract: In one embodiment, a method includes making a determination whether to modify a cleaning cycle, e.g., of a tape drive, based at least in part on at least one of: an age of one or more tapes, a type of one or more tapes, and an identity of a vendor of one or more tapes. A selection and/or modification of a timing of a cleaning operation is made based on the determination.

Abstract: A system, according to one embodiment, includes a tape drive configured to detect a telescoping condition of a magnetic recording tape and output an error alert when the telescoping condition is detected. Furthermore, a method, according to another embodiment, includes detecting a telescoping condition of a magnetic recording tape in use in a tape drive, and outputting an error alert when the telescoping condition is detected.

Abstract: Magnetoresistive (MR) bias is dynamically controlled in a tape drive using a processor device. Median tape head amplitude is monitored during a calibration operation, as measured across all tracks of the tape head, against predetermined thresholds of the tape drive for determining if the median tape head amplitude is below the threshold value. Upon determining the median tape head amplitude is below the threshold value during the calibration operation, a reference MR bias and a MR bias range is dynamically adjusted, during the calibration operation, for increasing the median tape head amplitude.