Patent ID: 8089712

Claim:
An abnormality determining apparatus comprising: a counting unit that counts a number of errors not attributable to a recording medium provided in a storage device and a number of accesses to the recording medium within a predetermined period; and an abnormality determining unit that calculates an error determining coefficient which indicates an amount of increase of the number of errors per unit number of accesses based on results of counting by the counting unit and determines whether the storage device is abnormal by comparing the error determining coefficient and a plurality of prescribed values, the abnormality determining unit determines that the storage device is abnormal when the error determining coefficient is in excess of a first prescribed value which indicates tolerable response lowering, the error determining coefficient is in excess of a second prescribed value which is obtained by multiplying the number of accesses that enables abnormality determination by a predetermined coefficient, and the number of accesses within the predetermined period is equal to or greater than a predetermined number.