Patent ID: 6397347
Filing Date: 2002-05-28
Classification: G06F

Abstract:
A disk array apparatus which comprises a plurality of disk units so as to have a redundancy and which carries out, in response to a data writing instruction or a data reading instruction from a host computer, a data writing operation or a data reading operation between the disk units of said disk array apparatus and said host computer in a normal mode, said disk array apparatus comprising:detecting means for detecting, as a faulty unit, one of said disk units in which an abnormality occurs on any one of said data writing operation and said data reading operation; memorizing means for memorizing information indicative of said faulty unit; disconnecting managing means for managing disconnection of said faulty unit by temporarily disconnecting said faulty unit as a temporarily disconnected unit to make said disk array apparatus operate in a temporary degenerate mode; instruction-execution controlling means for controlling instruction-execution to force the disk units except said temporarily disconnected unit to execute the data writing operation or the reading operation between the disk units except said temporarily disconnected unit and said host computer by the use of said redundancy when said disk array apparatus receives, during said temporary degenerate mode, the data writing instruction or the data reading instruction from said host computer; and retry means for carrying out retry for said temporarily disconnected unit in parallel to the data writing operation or the data reading operation executed between the disk units except said temporarily disconnected unit and said host computer.