G11B2020/1823

End-to-end fixity check for archival storage based on high-performance integrity test with data quality using self-describing tape format

A method for ensuring data quality integrity on a magnetic tape includes the steps of writing object data to the magnetic tape; dividing the object data into a plurality of data chunks; generating a hash tree from the plurality of data chunks, the hash tree being formed in a plurality of levels, the hash tree including (i) a plurality of chunk hashes wherein a separate chunk hash is generated for each of the plurality of data chunks, and (ii) at least one second level hash that is generated from concatenation of at least two of the plurality of chunk hashes; and checking integrity of a first data chunk of the plurality of data chunks by evaluating at least one of the plurality of chunk hashes and the at least one second level hash.

Identifying a defect in a data-storage medium

An embodiment of a data-read path includes a defect detector and a data-recovery circuit. The defect detector is operable to identify a defective region of a data-storage medium, and the data-recovery circuit is operable to recover data from the data-storage medium in response to the defect detector. For example, such an embodiment may allow identifying a defective region of a data-storage disk caused, e.g., by a scratch or contamination, and may allow recovering data that was written to the defective region.

Detecting media defects

A method according to one embodiment includes instructing a drive to detect a written signal burst on a magnetic tape and stop movement of the tape in response to detecting the written signal burst. A search for a defect is conducted in a location proximate to the written signal burst. An apparatus according to one embodiment includes a plurality of detector structures positioned in an array. Each of the detector structures includes a pair of conductive layers separated by an insulating material. A write transducer is aligned with each of the detector structures. A controller is configured to cause one of the write transducers to write a signal burst in response to the associated detector structure encountering a defect.

NONVOLATILE MEMORY DEVICE AND MEMORY SYSTEM INCLUDING NONVOLATILE MEMORY DEVICE
20220004457 · 2022-01-06 ·

A nonvolatile memory device performs a compare and write operation. The compare and write operation includes reading read data from memory cells, inverting first write data to generate second write data, adding a first flag bit to the first write data to generate third write data and adding a second flag bit to the second write data to generate fourth write data, performing a reinforcement operation on each of the third write data and the fourth write data to generate fifth write data and sixth write data, and comparing the read data with each of the fifth write data and the sixth write data and writing one of the fifth and sixth write data in the memory cells based on a result of the comparison.

Nonvolatile memory device and memory system including nonvolatile memory device

A nonvolatile memory device performs a compare and write operation. The compare and write operation includes reading read data from memory cells, inverting first write data to generate second write data, adding a first flag bit to the first write data to generate third write data and adding a second flag bit to the second write data to generate fourth write data, performing a reinforcement operation on each of the third write data and the fourth write data to generate fifth write data and sixth write data, and comparing the read data with each of the fifth write data and the sixth write data and writing one of the fifth and sixth write data in the memory cells based on a result of the comparison.

Detecting damaged areas on magnetic tape based on measuring a number of servo errors

A computer-implemented method, according to one embodiment, includes: receiving, from a tape drive, a first error location on a magnetic tape where a first error occurred, in addition to determining one or more areas on the magnetic tape to be examined based on the first error location. Independent of a read and/or write operation, the tape drive is instructed to induce 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. Moreover, each of the one or more areas having a respective number of measured servo errors which exceeds a threshold value is identified as a damaged area of the magnetic tape.

Detecting damaged areas on magnetic tape based on measuring a number of servo errors

A computer program product, according to one embodiment, includes a computer readable storage medium having program instructions embodied therewith. The program instructions are readable and/or executable by a processor to cause the processor to: determine, by the processor, a first error location on a magnetic tape where a first error occurred. One or more areas on the magnetic tape to be examined are also determined, by the processor, based on the first error location. Independent of a read and/or write operation, relative motion between a tape head and the magnetic tape is induced by the processor, such that the tape head is positioned adjacent to each of the one or more areas in turn. Moreover, each of the one or more areas having a respective number of measured servo errors which exceeds a threshold value are identified, by the processor, as a damaged area of the magnetic tape.

Reduced adjacent track erasure from write retry

Systems and methods are disclosed for reducing adjacent track erasure from write retry operations. In certain embodiments, an apparatus may comprise a circuit configured to abort a write operation while writing to a selected sector of a disc storage medium during a first revolution of the disc storage medium, and mark the selected sector as a temporary bad sector in a mapping table. The circuit may perform a write retry to continue the write operation starting at a next sector contiguously following the selected sector, without attempting to write the selected sector again, during a second revolution of the magnetic disc.

NONVOLATILE MEMORY DEVICE AND MEMORY SYSTEM INCLUDING NONVOLATILE MEMORY DEVICE
20200183784 · 2020-06-11 ·

A nonvolatile memory device performs a compare and write operation. The compare and write operation includes reading read data from memory cells, inverting first write data to generate second write data, adding a first flag bit to the first write data to generate third write data and adding a second flag bit to the second write data to generate fourth write data, performing a reinforcement operation on each of the third write data and the fourth write data to generate fifth write data and sixth write data, and comparing the read data with each of the fifth write data and the sixth write data and writing one of the fifth and sixth write data in the memory cells based on a result of the comparison.

DETECTING DAMAGED AREAS ON MAGNETIC TAPE MEDIA USING DIAGNOSTICS LOCATE

A computer program product, according to one embodiment, includes a computer readable storage medium having program instructions embodied therewith. The program instructions are readable and/or executable by a processor to cause the processor to: determine, by the processor, a first error location on a magnetic tape where a first error occurred. One or more areas on the magnetic tape to be examined are also determined, by the processor, based on the first error location. Independent of a read and/or write operation, relative motion between a tape head and the magnetic tape is induced by the processor, such that the tape head is positioned adjacent to each of the one or more areas in turn. Moreover, each of the one or more areas having a respective number of measured servo errors which exceeds a threshold value are identified, by the processor, as a damaged area of the magnetic tape.