International Business Machines Corporation

Facebook, Inc.

Wlodzimierz Stanley Czarnecki

Icko E T Iben

Robert G Biskeborn

Hugo Eric Rothuizen

Ernest Stewart Gale

Said Abdullah Ahmad

Jason Liang

Lee Curtis Randall

David Lee Swanson

Yu Cai

John Mah

A computer-implemented method includes, by one or more processors in electronic communication with a tunneling magnetoresistive sensor, wherein the tunneling magnetoresistive sensor is a component of a magnetic storage drive configured to read magnetic data from a magnetic storage medium, detecting a short across the tunneling magnetoresistive sensor, measuring a change in resistance of the tunneling magnetoresistive sensor, measuring a change in voltage amplitude for the tunneling magnetoresistive sensor, and dividing said change in voltage amplitude by said change in resistance to yield a ratio. The computer-implemented method further includes, responsive to the ratio being greater than a predetermined ratio threshold, determining that the short is caused by a magnetic shunt. A corresponding computer program product and computer system are also disclosed.

Diagnostics in TMR sensors

A method includes determining whether a tunneling magnetoresistance (TMR) sensor is corroded using resistance, amplitude and signal to noise ratio (SNR) measurements of the sensor. A method to determine whether a TMR sensor is corroded includes determining an expected initial resistance value, Rand measuring a resistance value, R, of the sensor. The method includes calculating a ratio of the Rvalue and the expected initial resistance value, Rand determining whether the ratio is in a predefined range for the TMR sensor. In response to determining that the ratio of the sensor is within the predefined range, the method includes outputting an indication that the TMR sensor is corroded. In response to determining that the ratio of the sensor is outside the predefined range, the method includes outputting an indication that the TMR sensor is not corroded.

Setting bias currents and limiting corrosion in TMR sensors

Data set groups are determined, wherein each data set group includes a plurality of data sets and each data set includes error-correcting information for content user data of the data set. One or more versions of data set group level error-correcting information for each data set group are calculated. The data set groups on stored a tape storage media. After the data set groups are stored, an amount of storage available on one or more regions of the tape storage media associated with one or more tape edges is identified. An instruction is provided to store at least a partial amount of the calculated one or more versions of data set group level error-correcting information for the data set groups able to be stored in the amount of storage available on the one or more regions of the tape storage media associated with the one or more tape edges.

Adaptive-rate error correction layer for tape storage

Embodiments of the present invention provide methods, systems, and computer program products for compensating for loss of current through shorted tunneling magnetoresistance (TMR) sensors. In one embodiment, for a magnetic head having multiple TMR read sensors, a first voltage limit is set for most parts and a second voltage limit is set for all of the parts. A number of TMR read sensors which are allowed to function between the first and the second voltage limits is determined using a probability algorithm, which determines the probability that the application of the second voltage limit will result in a dielectric breakdown within an expected lifetime of a drive is below a threshold value. For the number of TMR read sensors which are allowed to function at voltages between the first and second voltage limits, a determined subset of those sensors are then allowed to function at the second voltage limit.

Compensating for loss of current through shorted tunneling magnetoresistance sensors

Preventing accumulations on read/write (R/W) elements of a tape appliance tape head. Power and current to the R/W elements of the tape head are turned off. A tape head cycle using a tape cartridge is then performed. In another aspect of the invention, the tape cartridge is a standard tape cartridge. Tape processing of the standard tape cartridge is suspended. The tape head cycle is performed using the standard tape cartridge. Tape processing of the standard tape cartridge is then resumed.

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Palo Alto, CA, United States of America

Wlodzimierz Stanley Czarnecki