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.

A method includes moving a heat-assisted magnetic recording head relative to a magnetic recording medium comprising a plurality of tracks, the head comprising a reader and a writer including a near-field transducer (NFT) optically coupled to a laser diode, the writer comprising a center which is laterally offset relative to a center of the reader to define a writer-reader offset (WRO) therebetween. Patterns are written to a particular track at a plurality of laser diode current levels. The patterns are read and a WRO value is calculated at a peak amplitude position for each of the laser diode current levels. A slope of the WRO values is determined with the laser current diode levels. A health condition of the NFT is determined by determining if the slope is greater than a predetermined threshold indicative of non-uniform activation across the NFT.

Systems and methods are provided for reusing existing test structures and techniques used to test memory data to also test error correction code logic surrounding the memories. A method includes testing a memory of a computing system with an error code correction (ECC) logic block bypassed and a first data pattern applied. The method further includes testing the memory with the ECC logic block enabled and a second data pattern applied. The method also includes testing the memory with the ECC logic block enabled and the first data pattern applied.

A control method for a memory device uses an inverting data to label that a data stored in a memory block is in an inverting state or a non-inverting state. According to the inverting data, the number of bits whose data states is changed is lower than a half of total bits in the memory block in writing operation. Therefore, an energy consumption of the memory device can reduce. The control method of the present invention also can utilize the inverting data to label a memory block with a defective bit and to select a spare block to repair the memory block with a defective bit.

A data storage device is disclosed comprising a head actuated over a magnetic media, wherein the head comprises a write coil, a laser configured to heat the magnetic media during a write operation, and a read element. A test pattern is written to the magnetic media by applying a current to the write coil and a first bias to the laser. A second bias is applied to the laser while the head passes over the test pattern, and then the test pattern is read from the magnetic media using the head to generate a first read signal. A first noise power of the first read signal is measured, and at least one parameter of a noise power function is generated based on the first noise power measurement, wherein the noise power function is a function of at least the bias applied to the laser.

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.

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.

A hard disk drive includes a base deck, a cover coupled to the base deck to create an internal cavity, and a testing assembly coupled to the cover. The testing assembly includes a housing and is arranged to expose an organic material, for example grease or oil, to the internal cavity.

A hard disk drive includes a base deck, a cover coupled to the base deck to create an internal cavity, and a testing assembly coupled to the cover. The testing assembly includes a housing and is arranged to expose an organic material, for example grease or oil, to the internal cavity.

A method includes generating a plurality of blocks of a block chain wherein the plurality of blocks is associated with components of a storage device. The plurality of blocks is generated by a device other than the storage device when the components are manufactured. The method further includes storing a copy of a ledger associated with the generated blocks on the storage device when the storage device comprises computing power sufficient to generate blocks of a block chain. The method also includes generating additional blocks of the block chain. The additional blocks of the block chain are associated with additional components of the storage device when the additional components are manufactured. The additional blocks are generated independently by the device and by the storage device and wherein respective ledgers are updated.