Abstract: A method includes detecting a read error during a first read operation by a read sensor on a first track on a data storage medium. The method also includes, after the read error is detected, performing a second read operation by the read sensor on the first track, carrying out bit error value (BEV) measurements for the second read operation, and determining, from the BEV measurements, whether the read sensor produces a marginal BEV, which is between first and second predetermined BEV thresholds. In response to determining that the read sensor produces the marginal BEV, a third read operation by the read sensor on the first track is carried out, and BEV measurements for the third read operation are performed. When the BEV measurements from the second and third read operations meet at least one predetermined read sensor instability criterion, it is concluded that the read sensor is unstable.

Abstract: A system and method for performing read retry operations with respect to an erroneously read data sector is disclosed. The system and method use estimates of bit error rates determined during previous attempts to read data from the sector to determine an optimal distance and direction to move a read transducer for a subsequent read retry of the erroneously data sector.

Abstract: A system and method for performing read retry operations with respect to an erroneously read data sector is disclosed. The system and method use estimates of bit error rates determined during previous attempts to read data from the sector to determine an optimal distance and direction to move a read transducer for a subsequent read retry of the erroneously data sector.