JPH06337836A - Multiple address type bus interface for peripheral equipment - Google Patents

Abstract

PURPOSE:To provide a file device in which the management of plural disk file devices from a host computer is facile and whose response is satisfactory. CONSTITUTION:The external storage device of the computer is provided with a bus interface consisting of a command sequence control mechanism 221 analyzing a disk read/write request from the host computer 21 and controlling the file device, a command issuing mechanism 222 which can transmit the read/write request of data from the host computer to all the disk files, plural bus interface control mechanisms 23A and 23B which judge whether the read/write request from the host computer 21 can be executed or not and which can issue a bus request, disk devices 25A and 25B and a data bus arbiter 223 executing arbitration for the bus request from the plural disk file devices.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary storage device of a computer, and more particularly to an interface device between a host computer and the secondary storage device.

[0002]

2. Description of the Related Art As computer systems have become more sophisticated and complex, the number of intelligent devices for exchanging high-level messages has also increased regarding the interface with peripheral devices. For example, ANSI X3 / 131-1986 "Small Com
puter Interface ". In such a system, it is possible to perform detailed hardware control in each peripheral device so as not to place a burden on the host computer side. However, such a secondary storage device Then, on the host computer side, after specifying the disk device that exchanges data and the sector address of the transfer destination,
It only operates in response to predetermined simple input / output messages such as reading or writing data, and management of where and how data is physically stored is still on the host computer. Has been done by the operating system. Therefore, it is necessary to manage the secondary storage device such as a disk device while being aware that it is a plurality of independent devices.

[0003]

In the interface conventionally used for a disk file device, an I / O request to a disk is a command in the form of a packet in which information for specifying a file device and a theoretical sector address are specified. Are exchanging. At the same time, it is necessary to replace the logical sector address with the physical sector address on the driver software and specify the disk device (Japanese Patent Laid-Open No. 02-278362: Data Transfer Control Method). Therefore, even in the case of an intelligent interface such as SCSI, it is difficult to manage the file device regardless of the physical information (JP-A-60-103474: Disk control system).

Therefore, even in the case of using the intelligent interface, in the file management,
It is necessary to use physical information regarding the storage location of input / output data and manage it on the host computer side. Therefore, in a usage environment that mixes various devices and multiple drives, it becomes necessary to manage each,
Management was complicated (Japanese Patent Laid-Open No. 63-079156:
Data processing device).

Further, when specific data is called from a large amount of data, the information for managing the data is also stored in the secondary storage device, so the number of times of access to access the target data is reduced. Increase and cause deterioration of system performance.

[0006]

In the present invention, the following means are used to achieve the above object.

(1) In a bus interface of a computer external storage device composed of a plurality of file devices, a command sequence control mechanism (221), a command issuing mechanism (222) and a data bus arbiter (22)
The command sequence control mechanism (221) interprets read and write requests from the host computer (21) to and from the file device, and controls the file device. 21), a command issuing mechanism (222), a data bus arbiter (222), a status signal group, and a data bus (29), and the command issuing mechanism (222) receives data from the host computer (21). Read and write requests of the data bus arbiter (2) are simultaneously transmitted to the plurality of file devices and are connected to the command sequence control mechanism (221) and the target selection signal 27.
22) performs arbitration for bus requests from a plurality of the file devices, and is provided in a state of being connected to the command sequence control mechanism (221) and the bus request signal and use approval signal group (28). Bus interface characterized by.

(2) In a bus interface of a computer external storage device composed of a plurality of file devices, a command sequence control mechanism (321), a command issuing mechanism (322) and a data bus arbiter (32)
3), the command sequence control mechanism (321) interprets a read / write request from the host computer (31) to the file device and controls the file device. 31), the command issuing mechanism (322), the data bus arbiter (322), the status signal group and the data bus (39), and the command issuing mechanism (322) receives data from the host computer (31). Read and write requests of the command sequence control mechanism (321) and the target selection signal (3).
The data bus arbiter (323) is connected to 7), determines the executability of an input / output request from the host computer (31), and needs an additional input / output request to execute the request. When judged, the input / output can be reissued, and arbitration for bus requests from the plurality of file devices is performed. The host computer (31), the command issuing mechanism (322),
A bus interface provided in a state of being connected to a data bus arbiter (323), a status signal group (36) and a data bus (39).

[0009]

The present invention realizes the data transfer between the host computer and the secondary storage device by realizing the high-level data input / output protocol device in the secondary storage device of the computer without considering the storage location of the stored data. To do. Along with that, in a file server that needs to centrally manage a large amount of data, management becomes easy even in a usage environment in which a large number of or various devices coexist.
It is possible to manage the system configuration according to the application.

[0010]

[Embodiment] One embodiment according to claim 1 (first embodiment)
Will be explained.

FIG. 1 is a data processing flow according to the present invention.

FIG. 2 is a block diagram. The same applies to the case where a plurality of different devices such as a hard disk and a magnetic tape are mixed as the secondary storage device. FIG. 1 shows a transfer sequence in transmitting and receiving commands and data between the bus interface on the host computer 21 side and the disk side bus interface, and each processing name is a phase name.

When there is no access request to the secondary storage device, the host computer 21 normally waits for a bus request in the bus free phase. When an access request to the secondary storage device occurs, the bus is acquired and the command phase is entered. In the command phase, the command is issued to all the disk files to be data-transferred, and then the bus is released to shift to the bus-free phase.

If the interface control mechanism, which cannot transfer data in response to the data transfer request, can use the data bus, the interface arbitration phase is entered again. If 1
If there is no data bus use request during the fixed period, the command sequence control mechanism unit 221 determines that there is no data for input / output from the host computer 21, identifies the data transfer device, and then returns the status. The phase shifts to the phase and the transfer sequence is terminated because there is no target data.

In the bus arbitration phase, a disk-side bus interface controller that issues a data bus 29 use request based on the priority of the disk-side bus-free phase control mechanism registered in advance in the host-computer-side bus-free-face control mechanism 22. 23A structure is selected. Then move to the message phase.

In the message phase, the disk side bus interphase control mechanism that acquired the bus in the bus arbitration phase causes the host computer 21
The length of data to be actually transferred, the command packet to be executed on the disk, and the information when the bus is released in the middle are also notified to the side bus interface control mechanism. Then move to the data phase.

In the data phase, input / output based on the transfer format transmitted in the message phase is executed. In the status phase, if the data transfer is completed normally, the status of normal completion is returned. If any error occurs during data transfer, the error status is returned.

Next, the block structure of the interface will be described with reference to FIG. In the interface of the present invention, a data input / output request received from the host computer 21 is passed to the command sequence control unit 221, and the command issuing mechanism 222 selects all file devices using the target selection signal 27 in the command phase. Then, the command sequence control mechanism 221 issues a command on the data bus 29. After issuing the command, the command sequence control mechanism 221 releases the bus. When selected by the target selection signal 27, the disk data management mechanism 232A or 232B in the disk-side bus interface mechanisms 23A and 23B causes the data bus 2 to operate.
The command signal on 9 is monitored, and the holding data management table held in the disk side bus interface 23A or 23B is used to check whether the data matching the request exists in the disk file device. At that time, the disk devices 25A and 25B are read out via the desk controllers 24A and 24B as necessary, and the data collation is executed. If the data transfer request can be executed, the data bus requester 231A or 231B requests the data bus 29 using the bus request signal 28.
The command sequence control mechanism 221 receives the data bus requests from the plurality of disk side interface control mechanisms 23A and 23B, judges the pre-registered priority order, and uses the bus use approval signal 28 and the target selection signal 27 to determine the disk side bus interface. Select the control mechanism 23A or 23B. Disk side bus interface control mechanism 23A or 2 which has acquired the right to use the data bus 29
3B sends the data transfer method as a message to the interface on the host computer side in the message phase, and then executes the data transfer in the data phase.

Next, one embodiment (second embodiment) according to claim 2 will be described with reference to FIGS. 1 and 3. This is performed by the transfer sequence shown by the broken line in FIG. FIG. 3 is a block diagram according to claim 2 of the present invention. Here, a hard disk device 3 is used as a secondary storage device.
Although two 5A are shown, the same can be applied to the case where a plurality of different devices such as an optical disk and a magnetic tape are mixed as the secondary storage device.

In the interface of the present invention, in response to the data input / output request received from the host computer 31, the command sequence controller 321 causes the command issuing mechanism 322 to select all the file devices by using the target selection signal 37 in the command phase. Then, the command sequence control mechanism 321 issues a command on the data bus. After issuing the command, the command sequence control mechanism 321 releases the bus. Target selection signal 3
When selected in 7, the disk side bus interface mechanism 3
The disk data management mechanism 332A or 332B in 3A and 33B monitors the command signal on the data bus 39, and the disk side bus interface 33A or 33B.
By using the retained data management table retained in the above, it is verified whether or not the data matching the request exists in the disk file device. At that time, if necessary, the disk device 35 is passed through the disk controllers 34A and 34B.
Read the retained data management table from A and 35B,
Run the data. The disk data management mechanism 332A or 332B determines whether all or some of the data input / output requests from the host computer 31 can be executed. When it is determined that all input / output can be executed for the physical block requested by the host computer 31, the status signal group 36 is output as a status of complete execution, and at the same time the data bus requester 33 is output.
1A or 331B requests the data bus 39. When the disk data management mechanism 332A or 332B determines that a physical block for which a data input / output request is made can partially execute input / output, one fixed period status signal group 3
6 is monitored, and as a result, when another device does not output the request for the data bus 39 together with the status information that can be completely executed, the data input / output request from the host computer 31 can be executed to the other device at that time. It is determined that there is no such device, and this device outputs a partial executability status to the status signal group 36 at the same time as determining that this device can partially execute input / output.
The requester 331A or 331B requests the data bus 39. When the data bus 39 is acquired, physical input / output processing is not executed except for a physical block part that partially executes input / output processing in the disk side bus interface module in the input / output request from the host side. Regarding the block part, after the command issuing mechanism reissues the command to notify whether there is another device that can be processed, the partial execution process is executed through the message phase and the data phase. On the other hand, in the host computer side bus interface 32, the command sequence control mechanism 321 receives the data bus requests from the plurality of disk side interface control mechanisms 33A and 33B, judges the pre-registered priority order, and judges the bus use approval signal 3
8 and the target selection signal 37 are used to select the disk side bus interface control mechanism 33A or 33B.
At that time, the status signal group 36 is monitored, and the bus is preferentially assigned to the status that can be executed for one fixed period, and if the status that is completely executable cannot be obtained even after one fixed period, After issuing the partial execution status, the right to use the data bus 39 is given to the device requesting the bus.

In this way, the host computer 31
From the above, it becomes possible to issue a data input / output request without being aware of which file device the data is stored on. By using the apparatus according to the second aspect, even when data is stored over a plurality of file devices, a single input / output request command input / output process from the host computer 31 can be executed.

[0022]

As described above, the present invention realizes an intelligent secondary storage device which is not aware of the recording data format by implementing a higher level data input / output protocol device in the secondary storage device of a computer. By providing such a function to the secondary storage device, it becomes easy to handle data which has conventionally been difficult or complicated to manage by the host computer and the secondary storage device. Further, it is possible to provide only the minimum information required by the host from the host computer, and it is possible to minimize the data transfer amount between the hosts.

[Brief description of drawings]

FIG. 1 is a process flow chart for explaining one embodiment of a data transfer device of an intelligent secondary storage device according to claim 1;

FIG. 2 is a block diagram illustrating one embodiment of an intelligent secondary storage device according to claim 1;

FIG. 3 is a block diagram illustrating one embodiment of an intelligent secondary storage device according to claim 2;

[Explanation of symbols]

 21 host computer 22 host side bus interface control mechanism 221 command sequence control mechanism 222 command issuing mechanism 223 data bus arbiter 23A disk side bus interface control mechanism 23B disk side bus interface control mechanism 231A data bus requester 231B data bus requester 232A disk data management mechanism 232B Disk data management mechanism 24A Hard disk controller 24B Hard disk controller 25A Hard disk device 25B Hard disk device 26 Status signal group 27 Target selection signal 28 Bus request signal and specification approval signal group 29 Data bus 31 Host computer 32 Host side bus interface control mechanism 321 Command sequence Control mechanism 32 Command issuing mechanism 323 Data bus arbiter 33A Disk side bus interface control mechanism 33B Disk side bus interface control mechanism 331A Data bus requester 331B Data bus requester 332A Disk data management mechanism 332B Disk data management mechanism 333A Command issuing mechanism 332B Command issuing mechanism 34A Hard disk controller 34B Hard disk controller 35A Hard disk device 35B Hard disk device 36 Status signal group 37 Target selection signal 38 Bus request signal and specification approval signal group 39 Data bus

Claims (2)

[Claims] 1. A bus interface of a computer external storage device comprising a plurality of file devices, comprising a command sequence control mechanism, a command issuing mechanism, and a data bus arbiter, wherein the command sequence control mechanism is a host computer. From the host computer, the command issuer, the data bus arbiter, the status signal group and the data bus. The command issuing mechanism transmits the data read and write requests from the host computer to the plurality of file devices at the same time, and is connected to the command sequence control mechanism and the target selection signal. The data bus arbiter performs arbitration for bus requests from a plurality of the file devices, and is provided in a state of being connected to the command sequence control mechanism and the bus request signal and use approval signal group. Bus interface characterized by. 2. A bus interface of a computer external storage device comprising a plurality of file devices, comprising a command sequence control mechanism, a command issuing mechanism and a data bus arbiter, wherein the command sequence control mechanism is a host computer. From the host computer, the command issuer, the data bus arbiter, the status signal group and the data bus. The command issuing mechanism transmits the data read and write requests from the host computer to the plurality of file devices at the same time, and is connected to the command sequence control mechanism and the target selection signal. The data bus arbiter determines whether the input / output request from the host computer can be executed, and can reissue the input / output when it is determined that an additional input / output request is necessary to execute the request. Arbitration is performed for bus requests from a plurality of the file devices, and is provided in a state of being connected to the host computer, the command issuer, the data bus arbiter, the status signal group and the data bus. Bus interface characterized by.