JPH0594265A - Multiple writing filing system - Google Patents

Abstract

PURPOSE:To provide the multiple writing filing system which can take backup data from a relevant filing device without exerting any influence upon another device while operating the system. CONSTITUTION:First-third filing devices 10, 20 and 30 are the filing systems of triple writing to write the same data, are respectively internally provided with control parts 11, 21 and 31 and are also equipped with control functions to control the decode of commands received from first and second filing controllers 1 and 2 and data transfer and to cancel/reconstitute the construction of multiple writing. The respective filing devices 10, 20 and 30 respectively serially connect the first and second filing controllers 1 and 2 by file interface signal groups 101 and 102. Further, the respective filing devices 10, 20 and 30 are equipped with copy control circuits 12, 22 and 32 provided with processors and general interface control circuits and those circuits are serially connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplex file system, and more particularly to a multiplex file system having a plurality of file control devices and a plurality of file devices.

[0002]

2. Description of the Related Art In a conventional multiple write file system, a file device is multiplexed as a standby system for a data error caused by a failure of the file device or a defective medium. Therefore, if these reasons do not occur, writing is performed. Control to keep the data consistent, excluding the time of deviation,
Apparently it is handled as one disk device.

[0003]

The above-mentioned conventional multiplex file system is controlled so as to always keep the data consistent, and apparently handles it as one disk device. Therefore, for example, backup data is stored on a magnetic tape or the like. If you try to take it, stop the system operation and take a backup after this, or if you perform it during the system operation, the file device that takes the backup data will be occupied for a long time, so start from another device. However, there is a problem in that the operation of the system may be adversely affected and the operation of the system may be adversely affected.

An object of the present invention is to provide a multiplex file system which can take backup data from a corresponding file device without affecting other devices during operation of the system.

[0005]

A multiplex writing file system of the present invention is a multiplex writing file system having a plurality of file control devices of a multiplex writing structure for simultaneously reading and writing the same data and a plurality of file devices. Each device has a control unit that decodes commands received from the file control device and controls data transfer, and includes a control function for canceling and reconfiguring the multiplex structure, and canceling the multiplex structure and again defining the multiplex structure. And a copy control circuit for performing control for copying data from another file device after returning to.

The multiplex file system of the present invention may have a structure in which a command transmitted from the file controller for canceling and reconfiguring the multiplex structure issues individual instructions to a plurality of file devices.

[0007]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention.

The first file device 10, the second file device 20, and the third file device 30 are triple-written file systems in which the same data is written. Each of the file devices 10, 20, 30 has a control unit 1 inside.
1, 21 and 31 for decoding and controlling data transfer of commands received from the first file controller 1 and the second file controller 2 and canceling and reconfiguring the multiplex structure. It also includes a control function to operate.
Further, each of the file devices 10, 20, and 30 includes the first file control device 1 and the file interface signal group 101.
(Command line, bus-out line, etc.) and is also connected to the second file controller 2 by the file interface signal group 102. Further, each file device 10, 20, 30 has a copy control circuit 12, 22, 32 including a processor and a general-purpose interface (for example, SCSI) control circuit, which are connected to each other.

Next, the operation of canceling and reconstructing the multiplex structure will be described.

Each of the file devices 10, 20 and 30 receives and controls the command transmitted by either one of the file control devices 1 and 2. The command is configured as shown in the explanatory diagram for explaining the bit configuration of the bus-out in FIG.

First, as shown in FIG. 2 (A), the entire bus-out is composed of 8 bits, and each file device is designated by bits 0 to 2 and the file device address is designated by bits 3 to 7. I am trying. However, bit 3 is set to "0" during normal operation, and the address is indicated by bits 4 to 7.

For example, all file devices 10, 20, 30
In the case of the multiple writing configuration (hereinafter referred to as multiple writing mode), all bits 0 to 2 are set to "1" as shown in FIG.

During normal operation, bits 0 to 2 of the bus out are in multiple write mode, except for commands that must individually instruct the file device, such as reading the status of the file device. Then, the commands which are all set to "1" are sent from the file controller. Since the command for canceling and reconfiguring the multiple writing mode is a special command, it is issued by a file device individual instruction in which one of bits 0 to 2 is set to "1" as shown in FIG. In this case, only the third file device 30 is selected.

If a multiple write mode release command is issued from the file control device 2 to the third file device 30, the third file device 30 causes the control section 31 to decode the command. If it is recognized as a multiple writing mode release command, the address of the self device in the selection process from the next time is changed, and the response is changed when bit 3 is "1". It should be noted that bits 4 to 7 are the same as conventional ones. Further, the copy control circuit 32 notifies the first and second file devices 10 and 20 that the multiplex writing mode of the own device has been released. By doing this,
Next, even if the file controller 1 issues a command in which all bits 0 to 2 of the bus out are set to "1",
Since the third file device 30 does not respond, the multiple writing mode is released. In this case, the file control device 1 can know the cancellation of the multiple writing mode of the third file device 30 by looking at the contents of the status of the file devices 10 and 20.

In this state, when a command to save the volume of the third file device 30 is issued to the magnetic tape or the like, it is treated as a special command and the device address is converted by the file controller 2 or a higher-level device, and the command shown in FIG. As shown in the diagram (D), bit 3 of the bus out is set to "1", and the address of the third file device 30 is designated. Then, when the third file device 30 finishes this process, if the data of the first and second file devices 10 and 20 are updated during this process, the data of the third file device 30 will be stored. Are inconsistent, so
To restore the multiple writing mode again, it is necessary to copy the data of the first and second file devices 10 and 20 to the third file device 30. In this case, the file control device 2 issues a recovery command to the third file device 30, and the third file device 30 returns the bit 3 of the selected address to "0" by this instruction.
At this time, the copy control circuit 32 notifies the copy control circuits 12 and 22 of the first and second file devices 10 and 20 that the multiple write mode has been restored, and issues a data transfer request to either one. , Copy the data. In addition, since the third file device 30 receives the write instruction during this period, the data in the area after copying is
It matches the first and second file devices 10 and 20.

When the copying is completed, a collating operation for confirming the data may be performed with a file device different from the file device which copied the data.

[0018]

As described above, according to the present invention, backup data can be taken from a corresponding file device without affecting other devices during the operation of the system.
It has an effect.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a bus-out bit configuration.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st file control apparatus 2 2nd file control apparatus 10 1st file apparatus 11,21,31 Control part 12,22,32 Copy control circuit 20 2nd file apparatus 30 3rd file apparatus 101,102 File interface signal group

Claims (2)

[Claims] 1. In a multiplex file system having a plurality of file controllers having a multiplex structure for simultaneously reading and writing the same data and a plurality of file devices, each of the file devices is provided with a command received from the file controller. A control unit including a control function for controlling decoding and data transfer and for canceling and reconfiguring the multiplex structure, and for copying the data from another file device after canceling the multiplex structure and returning to the multiplex structure again And a copy control circuit for controlling the multiple write file system. 2. The multiplex file according to claim 1, wherein the command transmitted from the file controller for canceling and reconfiguring the multiplex structure has a structure for individually instructing a plurality of file devices. system.