The state or condition of a data storage drive, or a subsystem within a
drive, may be evaluated by comparing a set of selected parameter values,
converted into a trial vector, with a number of model or exemplar
vectors, each of which was represents a particular state or condition of
a sample drive. Examples of such conditions may include "good",
"marginal", "unacceptable", "worn", "defective", or other general or
specific conditions. Sets of parameter values from the drive are
converted into input vectors. Unprocessed vectors are then processed
against the input vectors in an artificial neural network to generate the
exemplar vectors. The exemplar vectors are stored in a memory of an
operational drive. During operation of the drive, the trial vector is
compared with the exemplar vectors. The exemplar vector which is closest
to the trial vector represents a state which most closely represents the
current state of the drive. Thus, a high similarity between the trial
vector and an exemplar vector which represent a "good" drive is likely to
have come from a "good" drive.