公开(公告)号：JPH0844497A

公开(公告)日：1996-02-16

申请号：JP11341395

申请日：1995-05-11

Applicant: IBM

Inventor： RICHIYAADO KENTO TORAIBAA ,  JIYONASAN MAABU HASUUERU ,  SUPENSAA WAA FUN NGU ,  YAMAGUCHI MARIO

IPC: G06F3/06 ,  G06F12/08

Abstract: PURPOSE: To provide a system for managing data transfer among a computer, data storage disk and data buffer related to the disk. CONSTITUTION: At the time of receiving a writing request during pre-reading from a disk 22 to a buffer 24, this system preferentially uses the pre-reading for writing data in the disk 22 only when a target writing track on the disk 22 is different from a track during the pre-reading to the buffer 24. Otherwise, the system continues the pre-reading until a target writing sector is positioned under a disk drive head. Also, at the time of receiving a reading request during cache writing from the buffer 24 to the disk 22, the system immediately fulfills the reading request before the cache writing is completed, when requested reading data are housed in the buffer 24. Moreover, this system performs dynamic switching between two polices: a data pre-reading preferential using policy and a data pre-reading non-preferential using policy, based on the parallel monitoring and comparison of a data request service time.