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.

公开(公告)号：JPH03134732A

公开(公告)日：1991-06-07

申请号：JP26798689

申请日：1989-10-17

Applicant: IBM

Inventor： NUMATA TSUTOMU ,  OGAKI KAZUTAKA ,  YAMAGUCHI MARIO

IPC: G06F5/14 ,  G06F5/10

Abstract: PURPOSE: To improve the utilization efficiency of a buffer by writing data in an area where the data are not stored regardless of the size relation of the value of a write pointer and the value of a read pointer. CONSTITUTION: The write pointer for specifying a write address and the read pointer for specifying a read address are provided and the value of the write pointer and the value of the read pointer are compared at all times in a comparator 5. Then, when the value of the write pointer and the value of the read pointer match, a pointer which caught up later is discriminated by a discrimination circuit 6 and an auxiliary discrimination circuit 13, write to the buffer is inhibited at the time of discriminating that the write pointers caught up later and read from the buffer is inhibited at the time of discriminating that the read pointer caught up later inversely. Thus, the buffer is effectively utilized.

公开(公告)号：JPH08235793A

公开(公告)日：1996-09-13

申请号：JP32736395

申请日：1995-12-15

Applicant: IBM

Inventor： YAMAGUCHI MARIO ,  HASHIMOTO MINORU ,  SAKAI TATSUYA ,  JIYON HAZUUERU

IPC: G06F3/06 ,  G06F11/10 ,  G11B20/12 ,  G11B20/18 ,  G11B27/10

Abstract: PROBLEM TO BE SOLVED: To improve the reliability by discriminating an error in correspondence between data held on a disk and addresses, and then store more information on the disk. SOLUTION: User data D when written is held in a register 46, and an error correction code ECC is generated by ECC generation algorithm Ar from both the user data D and its sector information (ID). The record consisting of the user data D and generated ECC is written on the disk; when the record is read out, the user data Dr of the read record Rr is. held temporarily in the register 46, the ECC is separated from the read record Rr, and an error check on the combined data of the user data D and sector information used as the address is made by ECC check algorithm. Only when it is judged by this error check that the sector information contains no error, the user data held in the register 46 is corrected and outputted to a host.

公开(公告)号：JPH11288358A

公开(公告)日：1999-10-19

申请号：JP560999

申请日：1999-01-12

Applicant: IBM

Inventor： TREIBER RICHARD K ,  HASWELL JONATHAN M ,  NG SPENCER W ,  YAMAGUCHI MARIO

IPC: G06F3/06 ,  G06F12/08

Abstract: PROBLEM TO BE SOLVED: To provide a computer disk drive system having a buffer to which a data preread/prefetch principle is selectively established by including a principle prefetch controller, etc., to receive the data from a user and to produce a prescribed signal as an answer to the data request. SOLUTION: A prefetch principle controller, etc., is prepared to receive the data from a user and to produce a prescribed signal as an answer to the data request. In this system, a disk drive controller 26 can selectively prefetch or interrupt the preread of data to a buffer 24. Thereby, a prefetch principle controller 32 instructs the prefetch of the preread of data to the buffer 24 when a request is received to obtain only the data that are stored in a disk 22. The controller 26 also includes a non-prefetch principle controller 34 which prevents the prefetch of the preread of data to the buffer 24 in the same situation where the prefetch should be originally permitted by the controller 32.