In one embodiment, a method includes writing a data set to a sequential access medium. The method also includes reading the data set immediately after being written to the sequential access medium in a read-while-write process to identify one or more faulty encoded data blocks, each of the one or more faulty encoded data blocks including at least one faulty codeword having symbols at least 10 bits in size. Moreover, the method includes rewriting a first of the one or more faulty encoded data blocks within a first encoded data block set to a particular logical track in the rewrite area of the sequential access medium selected from a predetermined subset of logical tracks. The predetermined subset of logical tracks includes D1+D2+1 logical tracks. Only one faulty encoded data block from a particular sub data set is rewritten in a single encoded data block set in the rewrite area.

A magnetic tape for use in a tape drive includes a plurality of tracks and a plurality of media defect characteristics. The plurality of tracks are laid out along a length of the magnetic tape, each of the plurality of tracks being configured to receive data that is organized into a plurality of fixed-size subdata sets each including a plurality of codeword interleaves. The data is laid out on the plurality of tracks in accordance with a tape layout allocation strategy as determined by a tape layout module. The tape layout module includes a tape layout optimization system that receives information on the plurality of media defect characteristics, the tape layout optimization system determining the tape layout allocation strategy based at least in part on at least one of the plurality of media defect characteristics; and the tape layout optimization system determining the tape layout allocation strategy further based on distance spectra between pairs of the plurality of codeword interleaves.

A computer-implemented method, according to one embodiment, includes: detecting a first error while accessing a magnetic tape, determining a first error location on the magnetic tape where the first error occurred, determining one or more areas on the magnetic tape to be examined, independent of a read and/or write operation, inducing relative motion between a tape head and the magnetic tape such that the tape head is positioned adjacent to each of the respective one or more areas in turn, using the tape head to measure a number of servo errors that occur in each of the respective one or more areas, and identifying each of the one or more areas having a respective number of measured servo errors which exceeds a threshold value as a damaged area of the magnetic tape. The one or more areas are determined using a predetermined algorithm which incorporates the first error location.

The present disclosure includes systems and methods for reducing rewrite overhead in a sequential access storage system. The method may comprise writing a data set to a sequential access medium using a magnetic head, wherein the data set comprises a plurality of encoded data blocks, classifying each of the plurality of encoded data blocks on the sequential access medium into one of at least three classes of write quality, and rewriting the encoded data blocks in a rewrite area of the sequential access medium based at least in part on the write quality class. In some embodiments, the at least three classes of write quality may comprise a hard rewrite class for which rewrites are necessary to prevent data loss, a soft rewrite class for which rewrites are desirable but not necessary, and a no rewrite class for which no rewrite is needed or desired.

A tape layout module for determining a tape layout allocation strategy for laying out data on tape, the data being organized into a plurality of fixed-size subdata sets with each of the plurality of subdata sets including a plurality of codeword interleaves, the tape including a plurality of media defect characteristics, includes a tape layout optimization system including a processor that receives information on the plurality of media defect characteristics. The tape layout optimization system determines the tape layout allocation strategy based at least in part on at least one of the plurality of media defect characteristics. Additionally, the tape layout optimization system can determine the tape layout allocation strategy further based on distance spectra between pairs of the plurality of codeword interleaves. Further, the tape layout optimization system can determine the tape layout allocation strategy by selectively utilizing at least one tape layout parameter.

A computer program product, according to one embodiment, includes a computer readable storage medium having program instructions embodied therewith. The computer readable storage medium is not a transitory signal per se. Moreover, the program instructions readable and/or executable by a processor to cause the processor to perform a method which includes: instructing, by the processor, a drive to detect a written signal burst on a magnetic tape; and searching, by the processor, a surface of the magnetic tape proximate to the written signal burst for a defect. A computer-implemented method, according to another embodiment, includes: moving a magnetic tape to an approximate location of a defect, detecting a written signal burst on the magnetic tape, and stopping movement of the magnetic tape in response to detecting the written signal burst. Other systems, methods, and computer program products are described in additional embodiments.

The present disclosure includes systems and methods for reducing rewrite overhead in a sequential access storage system. The method may comprise writing a data set to a sequential access medium using a magnetic head, wherein the data set comprises a plurality of encoded data blocks, classifying each of the plurality of encoded data blocks on the sequential access medium into one of at least three classes of write quality, and rewriting the encoded data blocks in a rewrite area of the sequential access medium based at least in part on the write quality class. In some embodiments, the at least three classes of write quality may comprise a hard rewrite class for which rewrites are necessary to prevent data loss, a soft rewrite class for which rewrites are desirable but not necessary, and a no rewrite class for which no rewrite is needed or desired.

A tape layout module for determining a tape layout allocation strategy for laying out data on tape, the data being organized into a plurality of fixed-size subdata sets with each of the plurality of subdata sets including a plurality of codeword interleaves, the tape including a plurality of media defect characteristics, includes a tape layout optimization system including a processor that receives information on the plurality of media defect characteristics. The tape layout optimization system determines the tape layout allocation strategy based at least in part on at least one of the plurality of media defect characteristics. Additionally, the tape layout optimization system can determine the tape layout allocation strategy further based on distance spectra between pairs of the plurality of codeword interleaves. Further, the tape layout optimization system can determine the tape layout allocation strategy by selectively utilizing at least one tape layout parameter.

A computer program product, according to one embodiment, includes a computer readable storage medium having program instructions embodied therewith. The computer readable storage medium is not a transitory signal per se. Moreover, the program instructions readable and/or executable by a processor to cause the processor to perform a method which includes: instructing, by the processor, a drive to detect a written signal burst on a magnetic tape; and searching, by the processor, a surface of the magnetic tape proximate to the written signal burst for a defect. A computer-implemented method, according to another embodiment, includes: moving a magnetic tape to an approximate location of a defect, detecting a written signal burst on the magnetic tape, and stopping movement of the magnetic tape in response to detecting the written signal burst. Other systems, methods, and computer program products are described in additional embodiments.

An apparatus according to one embodiment includes a first block, a second block, and a drive mechanism configured to cause a magnetic recording tape to move over the blocks. Each of the blocks has a skiving edge along a tape bearing surface thereof. The blocks are positioned or selectively positionable in the apparatus to establish a particular respective wrap angle of the magnetic recording tape approaching the respective skiving edge. None of the blocks have a transducer coupled directly thereto.