COMMAND PROCESSING METHOD FOR SCSI PROTOCOL AND DEVICE USED FOR THE PROCESSING METHOD

    公开(公告)号:JP2000132507A

    公开(公告)日:2000-05-12

    申请号:JP30526998

    申请日:1998-10-27

    Applicant: IBM

    Abstract: PROBLEM TO BE SOLVED: To provide a command processing method which is used for an SCSI (small computer system interface) protocol and can improve the system throughput and also to provide a device that can be used for the command processing method. SOLUTION: This command processing method is applied to the queuing with a tag having >=2 queue depth of an SCSI protocol. When the continuous write commands are processed, the end of each write command is detected and a response is returned to a host to notify the end of the writing. If the new commands which can be continuously processed are received against a command that is currently processed, the received new commands are added to the command under processing to dynamically extend the internal processing information. Thus, the received commands are executed continuously to the command under processing. In such a constitution, the system throughput can be improved.

    DEVICE AND METHOD FOR RECORDING AND REPRODUCING INFORMATION IMPROVING ACCESS METHOD TO SECTOR

    公开(公告)号:JPH1173757A

    公开(公告)日:1999-03-16

    申请号:JP22901997

    申请日:1997-08-26

    Applicant: IBM

    Abstract: PROBLEM TO BE SOLVED: To shorten the time for processing at every command by executing plural commands containing a first command and a second command sent from a host computer with once command in a device. SOLUTION: A CPU 19 judges whether or not a final address of a first sector address specified by the first command is adjacent with a top address of a second sector address specified by the second address when plural commands are sent from the host computer 22. When not adjacent, a not specified address existing between the first final address and the second top address is specified, and the commands accessing the first, second sector addresses are imparted to the specified address to be imparted to an HDC 17. An access means accesses the sector specified by the second command while skipping the not specified address after it accesses the sector specified by the first command.

    DISK DRIVE DEVICE AND ITS CONTROLLING METHOD

    公开(公告)号:JP2001022529A

    公开(公告)日:2001-01-26

    申请号:JP18470299

    申请日:1999-06-30

    Applicant: IBM

    Abstract: PROBLEM TO BE SOLVED: To obtain a disk drive device which prevents rotational delay that can occur in a multi-drive environment and can improve performance and its controlling method. SOLUTION: This device is provided with a microprogram consisting of a queue handler 7 which stores a plurality of commands issued by a host in a queue area, performs a reorder to decide a command to be carried out and a requests the decided command to be executed, an interface handier 8 which executes the processing of an interface side including data transfer between the host and a drive device 2 according to the command requested to be executed and a drive handler 9 which executes the processing of a drive side according to the command requested to be executed and requests the device 2 to perform reading/writing about the execution of the command, separates the processing of the interface side from the processing of the drive side about the command processing and prevents the processing of the interface side from affecting the start of the processing of the drive side.

    METHOD AND DEVICE FOR READING DATA

    公开(公告)号:JPH11110139A

    公开(公告)日:1999-04-23

    申请号:JP26236897

    申请日:1997-09-26

    Applicant: IBM

    Abstract: PROBLEM TO BE SOLVED: To make improvable the performance of inverse reading by starting reading data at an address preceding to a current address at the time point, when the reading of data from a storage medium is finished, when the inverse reading is detected. SOLUTION: A magnetic disk device 10 is provided with a magnetic disk 11, magnetic head 12, actuator mechanism 13, hard disk controller 17 and RAM 18 or the like. The hard disk controller 17 controls operation such as the read/ write of data to the magnetic disk 11. The RAM 18 temporarily stores the supplied data and caches recording/reproducing data. This data reading method is a data reading method for reading data from the storage medium and has an inverse direction detecting step for detecting the inverse reading and a step for starting reading data at the address preceding to the current address at the time point when data are completely read out of the storage medium.

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