Patent classifications
G11B2220/956
Partial reverse concatenation for data storage devices using composite codes
In one embodiment, a method includes writing data to a storage medium, via a write channel, by applying a partial reverse concatenated modulation code to the data prior to storing encoded data to the storage medium. The applying the partial reverse concatenated modulation code to the data includes application of a C2 encoding scheme to the data to produce C2-encoded data prior to application of one or more modulation encoding schemes to the C2-encoded data to produce modulated data, followed by application of a C1 encoding scheme to the modulated data subsequent to the application of the one or more modulation encoding schemes to produce the encoded data.
MAGNETIC TAPE AND MAGNETIC TAPE DEVICE
The magnetic tape includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic support, in which the magnetic layer has a timing-based servo pattern, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5.
MAGNETIC TAPE AND MAGNETIC TAPE DEVICE
The magnetic tape includes a non-magnetic support; a non-magnetic layer including a non-magnetic powder and a binding agent on the non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic layer, in which a total thickness of the non-magnetic layer and the magnetic layer is equal to or smaller than 0.60 m, the magnetic layer has a servo pattern, and an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5.
MAGNETIC TAPE, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE APPARATUS
The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. In a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer with a scanning electron microscope at an acceleration voltage of 5 kV, the number of bright regions having an equivalent circle diameter of 75 nm or more and less than 125 nm is 100 or more and 4000 or less, and standard deviation ? of the number of the bright regions in a width direction of the surface of the magnetic layer is 400 or less.
MAGNETIC TAPE, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE APPARATUS
The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. In a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer with a scanning electron microscope at an acceleration voltage of 2 kV, the number of dark regions having an equivalent circle diameter of 75 nm or more and less than 125 nm is 20 or more and 1500 or less, and standard deviation ? of the number of the dark regions in a width direction of the surface of the magnetic layer is 400 or less.
Dynamically optimizing read performance by adjusting servo-based head location
A computer-implemented method includes: determining a reading performance of a head at a commanded lateral reading location; adjusting a location of the head relative to a medium by moving the head in a first lateral direction to an adjusted lateral reading location; determining a reading performance of the head at the adjusted lateral reading location, and determining whether the reading performance at the adjusted lateral reading location is better than the reading performance at the commanded lateral reading location. In response to determining the reading performance is better at the adjusted reading location, the method includes iteratively repeating the adjustment of the location of the head until the reading performance of the head at a current iteration is worse than the reading performance of the head at an immediately previous iteration. Corresponding systems and computer program products are also disclosed.
Tape cartridge partial initialization
An example tape storage drive may include reading/writing circuitry and control circuitry. The reading/writing circuitry may be to read from and write to tape media of tape cartridges. The processing circuitry may be to, in response to a tape cartridge being loaded into the tape storage drive, validate initialization of the tape cartridge. The processing circuitry may be to, in validating initialization of the tape cartridge, determine whether a tape format portion of a cartridge memory of the tape cartridge contains tape format data and whether the tape format portion is write-locked. If the tape format portion contains tape format data and is not write-locked, then the processing circuitry may fully initialize the tape cartridge including selecting a tape format for the tape cartridge and updating the tape format data to specify the selected tape format, write-lock the tape format portion, and then deem initialization of the tape cartridge to be complete.
Method of writing file onto tape
An approach to reducing overhead to enable high-speed writing even when a large number of small-sized files are written onto a tape in a file system. The method of the present invention includes the steps of: writing multiple files consecutively onto a tape to become one combined file; writing, onto the tape, first index information including the start position and size of the combined file on the tape; and writing, onto the tape, second index information including the start position and size of each of the multiple files in the combined file on the tape.
DYNAMICALLY OPTIMIZING READ PERFORMANCE BY ADJUSTING SERVO-BASED HEAD LOCATION
A computer-implemented method includes: determining a reading performance of a head at a commanded lateral reading location; adjusting a location of the head relative to a medium by moving the head in a first lateral direction to an adjusted lateral reading location; determining a reading performance of the head at the adjusted lateral reading location, and determining whether the reading performance at the adjusted lateral reading location is better than the reading performance at the commanded lateral reading location. In response to determining the reading performance is better at the adjusted reading location, the method includes iteratively repeating the adjustment of the location of the head until the reading performance of the head at a current iteration is worse than the reading performance of the head at an immediately previous iteration. Corresponding systems and computer program products are also disclosed.
Dynamically optimizing read performance by adjusting servo-based head location
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.