Patent classifications
G11B20/1879
Detecting shingled overwrite errors
Systems and methods are disclosed for detecting shingled overwrite errors. When a read error is encountered when reading from shingled recording tracks, a processor may determine whether the read error is an error caused by shingled overwriting. The processor may determine whether the read error is caused by shingled overwriting by determining read signal quality of one or more sectors preceding the read error, such as based on a bit error count or bit error ratio (BER), and comparing the read signal quality to a threshold value. The processor may determine that the read error is caused by shingled overwriting when the read signal quality value is lower than the threshold.
Erasing recorded data by utilizing read head and write head
Techniques for reducing the time required for erasing specific data recorded on a tape medium. A specific group of records is erased without preliminarily locating the erasure end position. This is carried out by simultaneously utilizing three heads, that is, two read heads and one write head, to detect the erasure end position during data erasure. Various embodiments are applicable to tape media as well as other storage media. Various embodiments are not only applicable as a file system cooperating as a combination of hardware (H/W) and software (S/W), but also applicable in systems, such as databases, that directly use storage without an intermediary file system.
Magnetic disk device
According to one embodiment, during a first write period, an adjustment unit derives a first predicted excess amount and a predicted upper limit threshold value, and a correction limit prediction unit calculates a first cumulative predicted excess amount. The determination unit causes the write processing unit to continue the write processing if determining that the first cumulative predicted excess amount is smaller than or equal to the predicted upper limit threshold value, and causes the write processing unit to suspend the write processing if determining that the first cumulative predicted excess amount exceeds the predicted upper limit threshold value.