JPH10269030A - Remote file sharing system, and control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a remote file sharing system capable of sharing files from respective host devices between storage controllers performing remote double write. SOLUTION: To the write request of data from the host device 3, the storage controller 5 sets information to the shared file control information table 97 of a remote storage controller 6 so as to exclude the input/output instruction of the data from the host device 4. Thus, by excluding input and output from the host device 4 until the write of the data to both storage controllers is ended, this remote file sharing system is realized between the storage controllers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage system, and more particularly, to a storage system in which data on a storage medium is double-written between remote storage controllers without the intervention of a host device. The present invention relates to a remote file sharing system capable of reading / writing double-written data from a higher-level device connected to a remote device.

[0002]

2. Description of the Related Art A technique for transferring data between storage controllers without the intervention of a host device and realizing double writing of data between remote storage controllers, that is, remote double writing, is disclosed in United States Patent 5,155,845. It is described in. According to this conventional technique, when the primary storage control device receives a command designating the primary and secondary storage media under the storage control device from the host device, the data stored in the storage medium of the primary storage control device is transferred to the storage medium of the secondary storage control device. Copy the data.
At the same time, when the host device issues a write request to the primary storage control device, the primary storage control device stores the write data in the primary storage control device,
Issues a write request to the secondary storage controller.

[0005] Remote duplication is realized by the above operation. By performing remote dual writing, if the data in the primary storage controller becomes incapable of input / output due to a disaster or failure, the business is taken over by the secondary system consisting of the secondary storage controller and the secondary higher-level device connected to it. It becomes possible.

On the other hand, there is a technology and a file sharing system for sharing data stored in a storage medium under a storage control device from a plurality of higher-level devices. According to this conventional technique, when a higher-level device issues a data write request to the storage controller, the storage controller stores the data transferred from the higher-level device in a subordinate storage medium. During the writing process, when a read / write request for the data is issued from another higher-level device, the higher-level device that has issued a request that the data in the storage control device is being written and that the data cannot be operated. Report to According to the above processing, during a data write request process from the higher-level device to the storage control device, when a read request for the data is issued from another higher-level device, the data before writing is not read out,
Even when a write request for the data is issued from another higher-level device, the latter write process is not performed before writing.

[0005] By the above operation, data under the storage controller can be shared by a plurality of higher-level devices. By sharing a file with a plurality of higher-level devices, distributed processing that reduces the load on practical processing of each higher-level device becomes possible.

[0006]

In the above prior art, only when a system consisting of a primary host and a primary storage controller becomes unusable due to a disaster or a failure, etc. Since the business program is succeeded by using the data duplicated in the above, the secondary host device when no disaster or failure occurs has not been effectively used. As a solution to this, as in another conventional technique, data of a storage controller is shared from a plurality of higher-level devices. If no trouble or failure occurs, it is conceivable to disperse the practical processing.

In the case of remote file sharing, in order to process a data write request from the secondary host to the secondary storage controller, data is written from the primary host to the primary storage controller, which is a conventional remote dual writing technique. In addition to the request, receiving a write request from the secondary host device to the secondary storage control device and transferring the write data from the secondary storage control device to the primary storage control device, thereby performing remote duplex writing of data in two directions. Is required. Therefore, the first problem to be solved by the present invention is a system configuration that issues a data write request bidirectionally between the primary and secondary storage controllers and enables remote dual writing.

On the other hand, when the primary / secondary storage controller receives a data read / write request from a higher-level device, the data must be identical in the primary / secondary storage controller. However, in the conventional remote dual writing, when a primary host issues a data write request to the primary storage controller, the primary storage controller stores the data in a subordinate storage medium and the secondary storage controller To issue a data write request,
Between the time when data is stored in the subordinate storage medium and the time when the data is written to the secondary storage control device, a state where the data does not match between the primary and secondary storage control devices occurs. In particular, after data is stored in the storage medium under the primary storage control device, until the secondary storage control device receives a data write request,
The secondary storage control device cannot determine that the primary storage control device is in the process of requesting the writing of the data. Therefore, despite the data mismatch between the primary and secondary storage control devices, the secondary storage control device When a data read / write request is issued to the storage controller, there is no means for determining that the request cannot be processed. Therefore, a second problem to be solved by the present invention is to determine whether the storage control device can receive a read / write request from a higher-level device, that is, the storage controller has a read / write request from a higher-level device. Is not to be received, there is a means for exclusively controlling an input / output request from a higher-level device.

[0009]

In order to solve the first problem, the primary storage control device includes a transmission control circuit capable of transmitting an input / output request from the primary storage control device to the secondary storage control device, and a primary storage control device. A reception control circuit for receiving an input / output command from the control device to the primary storage control device; and a transmission control capable of transmitting an input / output request from the secondary storage control device to the primary storage control device also for the secondary storage control device. Circuit, and a reception control circuit for receiving an input / output command from the primary storage control device to the secondary storage control device.The transmission control circuit and the reception control circuit under the primary / secondary storage control device are connected, and the input / output instruction and It has a path for transferring data.

According to the present invention, a data read / write request from the primary storage control device to the secondary storage control device and a data read / write request from the secondary storage control device to the primary storage control device are provided.
/ With the function to process write requests, it is possible to issue write requests to duplicate data write requests from the primary / secondary upper-level devices to the primary / secondary storage controllers to the remote storage controllers. , Two-way remote duplex writing becomes possible.

On the other hand, in order to solve the second problem,
Each of the primary and secondary storage controllers has a table for storing information for exclusion of an input / output request from a higher-level device, and the primary and secondary storage controllers exclude input and output from the table controlled by each remote storage controller. It has a function to issue an instruction to write data position information.

According to the present invention, when a data write request is issued from a higher-level device to a storage controller, the storage controller transmits the data write request to a remote storage controller before storing the data in a subordinate storage medium. The remote host issues an instruction to exclude the input / output request of the data, the remote storage controller writes the exclusion information in the table, and then writes the data to a subordinate storage medium. Issue a request to write the data, and after storing the data in the remote storage controller, issue a command to release the exclusive information from the table to the remote storage controller.

According to the above operation, after the data is stored in the subordinate storage medium and before the data write request is issued to the remote storage control device, the remote host device transmits the data to the remote storage control device. Also, when a read / write request is issued, the table for storing exclusive information in the remote storage control device stores information for exclusion of input / output of the data from the higher-level device. Since the device excludes the input / output request from the remote host device, the device can report to the remote host device that the request cannot be processed.

As another means for solving the above first problem, a read / write request is issued to the primary and secondary storage controllers to a remote storage controller, and data is read / written from the remote storage controller. A transmission / reception control circuit having a function of receiving a request and a path connecting the transmission / reception circuits are provided. According to the present invention, when the control circuit of the primary storage control device is used for transmission, when the control circuit of the secondary storage control device is used for reception, and when the control circuit of the secondary storage control device is used for transmission, control of the primary storage control device is performed. By switching the operation of the circuit for reception, it is possible to issue an I / O request and transfer data bidirectionally with a single path, and to duplicately write data bidirectionally between storage control devices. Thus, the problem can be solved.

[0015]

FIG. 1 shows a configuration example of a remote file sharing system according to an embodiment of the present invention. In this configuration example, the system is composed of two computer systems, a computer system 1 and a computer system 2. Each has a host device 3, a storage control device, and in the configuration example, a magnetic disk control device 5.

In the conventional remote double-writing system, a computer system, a higher-level device, and a magnetic disk control device that are operated in normal times are called positive, and when the positive computer system becomes inoperable due to a disaster or failure, it takes over the business. The computer system, the host device, and the magnetic disk control device are called sub-devices. In the present invention, the remote file sharing allows both computer systems to operate from normal times, and since both computer systems require the same configuration and the same control, there is no difference in the configuration and control of both computer systems. Absent. However, for convenience or logic, the computer system 1 and the host device 3
The configuration and operation will be described with a focus on the magnetic disk controller 5 and, if necessary, the computer system 2, the host device 4 and the magnetic disk controller 6 will be referred to as remote, and the operation will be described.

The magnetic disk control device 5 is connected to the host device 3 and a remote magnetic disk control device 6 by paths 70, 72 and 73 capable of transferring input / output commands and data.

The internal structure of the magnetic disk control device 5 includes a magnetic disk 10 for storing data, control of input / output commands from a magnetic disk control device 6 remote from the host device 3, and
Control of input / output commands to the remote magnetic disk controller 6;
And a disk I / O control unit 8 for controlling the retrieval / storage of data to / from the magnetic disk.

The magnetic disk 10, as shown in FIG.
A plurality of disks 100 for recording data and a head 101 for reading / writing data on the disks
And an interface control circuit 104 that exchanges data with the disk I / O control unit 8.
A recording unit on a circle that can be accessed by the head during one rotation of the disk is called a track 102. A plurality of tracks exist on the disk 100 by moving the position of the head 101. When data is input / output from / to a certain track 102, the head 101 is positioned at this track 102 and data is input / output. Magnetic disk 1
0 has a plurality of disks and a plurality of heads corresponding to the disks, so that the heads other than the head 101 are simultaneously moved by the positioning operation. A group of tracks on which another head is positioned when the head 101 is positioned on a certain track 102 is called a cylinder 103. Cylinders are arranged in ascending order from the inside of the disk,
The heads are numbered in ascending order from the top, and are called a cylinder number and a head number, respectively.

The internal configuration of the disk I / O control unit 8 will be described. As shown in FIG. 3, a command reception control circuit 81 for receiving an input / output command from the host device 3 and transferring data, and a remote magnetic A command reception control circuit 82 for receiving an input / output command from the disk control device 6 and transferring data; a command transmission control circuit 83 for transmitting an input / output command to the remote magnetic disk control device 6 and transferring data; A data transfer control circuit 84 for transferring data from the magnetic disk 10 to the respective command transmission / reception control circuits, a processor 85 for controlling the above-described control circuits using a control line 89, and operating on the processor 85. A file is shared between the memory 86 storing the magnetic disk control program and the remote magnetic disk controller 6. And a shared file control information table 87 for storing exclusive control information.

FIG. 4 shows the shared file control information table 87.
An example of the configuration will be described. In general, the magnetic disk control device controls a plurality of magnetic disks.
As shown in FIG. 4, the vertical axis is divided into cylinders and the horizontal axis is divided by magnetic disks, and information for exclusive control is provided for each magnetic disk in units of cylinders. Table value to be set to 1
If no exclusion is required, 0 is set. Therefore, when the magnetic disk controller 5 receives a command for exclusion of input / output from the remote magnetic disk controller 6 and a cylinder number for exclusion, the data on the table corresponding to the cylinder number is set to 1, and When receiving the command to release the exclusion of the output and the cylinder number, the data in the table corresponding to the cylinder number is set to 1 to create the position information of the cylinder for which the input / output from the host device is excluded.

In the remote file sharing system according to the present embodiment, when a read / write command is issued from the higher-level device 3 to the magnetic disk controller 5, the operation of the magnetic disk controller 5 is controlled by the disk I / O controller 8 Will be described with reference to the flow of the disk control program of FIG.

In an initial state, the disk I / O control unit operates until the command reception control circuits 81 and 82 receive commands from the host device 3 and the remote magnetic disk control device 6 until the command is received.
In step 200, the command reception waiting state is maintained.

If a write command has been received from the higher-level device 3, the process proceeds to step 202, where it is confirmed whether or not the cylinder containing the write data is in the exclusive state by the magnetic disk controller 6 in the shared file control information table.
If exclusive, the host device 3 is notified that the write process cannot be performed, and the process returns to step 200. If exclusive, the command transmission control circuit in step 206 sends the remote magnetic disk controller 6 to the remote magnetic disk controller 6 in step 206. Host device 4
Issue a command requesting exclusion of the access to the relevant cylinder from the server, hereinafter an exclusion request command. Since the remote magnetic disk control device 6 that has received the exclusion request command is also operating according to the disk control program of FIG. 5, the exclusion request command is received in step 200 while waiting for the command reception. The relevant cylinder that excludes access from the host 4
Is not accessed, and if so, exclusion incomplete is reported to the magnetic disk controller 5. If not, the access of the cylinder to the shared file control information table 97 is performed in step 212. And reports the completion of the exclusion to the magnetic disk controller 5. Upon receiving the processing result of the exclusion request command, in step 207, if the exclusion processing has not been completed,
When the exclusive processing is completed, the write data is stored in the magnetic disk 10 in step 208, and a write command of the data is issued to the remote magnetic disk controller 6 in step 209. I do. When the writing of the data to the remote magnetic disk control device 6 is completed, in step 210, a command for releasing the exclusion request of the cylinder set in the remote magnetic disk control device 6 is issued. Data is duplicated between remote magnetic disk controllers.

When a read command is issued from the higher-level device 3, it is checked in step 202 whether the cylinder containing the data to be read is exclusive in the shared file control table. It reports that the data cannot be read, and if it is not exclusive, retrieves the data from the magnetic disk 10 in step 204 and transfers the read data to the host device 4 in step 205. At the time of the read command processing, the data on the magnetic disk 10 is not changed, so that the data to be double-written between the remote magnetic disk controllers maintains the matching state. Therefore, an exclusion request command is issued to the remote magnetic disk controller 6 as in the case of a write command,
It is not necessary to exclude the host device 4 from accessing the data.

With the above operation, only when a data mismatch occurs between remote magnetic disk controllers due to a write command from a higher-level device, remote magnetic disk control from a remote higher-level device other than the higher-level device that issued the write command. Since the access of the data to the device can be excluded, the double-written data between the magnetic disk controllers can be shared by the remote higher-level devices connected to the remote magnetic disk controller.

As another embodiment of the remote file sharing system configuration, a configuration example shown in FIG. 6 can be considered.

In FIG. 6, the magnetic disk controller 5
The transfer of commands and data between the controller and the magnetic disk controller 6 can be configured only by the path 74. That is, the path 74 transfers commands and data bidirectionally. FIG. 7 shows the internal configuration of the disk I / O control unit 8 which enables bidirectional transfer of commands and data via the path 74.

It is the command transmission / reception control circuit 80 that transmits / receives commands and data to / from the remote magnetic disk controller 6. The command reception control circuit 82 operates when a command is received. It has a function of switching the operation so that the command transmission control circuit 83 operates.

The transmission / reception control circuit normally performs a command reception waiting state, that is, a command reception control.
When the operation is switched, the processor 85 switches the operation to the command transmission control when a request to transmit a command to a remote magnetic disk control device occurs. Also,
After the processing of the transmitted command is completed, the mode is switched to the command reception control.

By performing the above-described dynamic switching processing, in the present invention, a remote file sharing system can be configured from a single path.

[0032]

According to the present invention, a table for setting exclusive information is provided in a storage controller, which is controlled, so that differently written data can be shared between different storage controllers from different upper-level devices. A possible remote file sharing system can be constructed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a computer system according to an embodiment of the present invention.

FIG. 2 shows an example of a hardware configuration of a magnetic disk according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a hardware configuration example of a disk I / O control unit according to the embodiment of the present invention;

FIG. 4 is a configuration example of a shared file control information table according to the embodiment of this invention.

FIG. 5 is a flowchart of a main program according to the embodiment of the present invention.

FIG. 6 is a block diagram showing a schematic configuration of a computer system according to an embodiment of the present invention.

FIG. 7 is a block diagram showing a hardware configuration of a disk I / O control unit according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Computer system, 3 ... Host apparatus, 5 ... Magnetic disk controller, 8 ... Disk I / O control part, 10 ... Magnetic disk, 70 ... Path, 72 ... Path, 73 ... Path, 8
DESCRIPTION OF SYMBOLS 1 ... Command reception control circuit, 82 ... Command reception control circuit, 83 ... Command transmission control circuit, 84 ... Data transfer control circuit, 85 ... Processor, 87 ... Shared file control information table, 97 ... Shared file control information table

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroaki Nakanishi 2880 Kozu, Odawara-shi, Kanagawa Storage Systems Division, Hitachi, Ltd.

Claims (4)

[Claims] A primary storage control device connected to a primary host device;
The secondary storage device is remote from the primary storage control device, and is composed of a secondary storage device different from the primary storage device and a secondary storage control device connected to the primary storage control device, and sends a data write request from the primary storage secondary device to the primary storage control device. In a computer system in which a storage medium controlled by a primary storage control device and a storage medium controlled by a secondary storage control device are remotely duplicated without passing through a higher-level device, data duplicated between the primary and secondary storage control devices This is a method of controlling a read / write request from the higher-level device by the storage controller as data that can be shared by the higher-level device.When a higher-level device issues a data write request to the storage controller, the storage controller: Issue a request to the remote storage controller to exclude the read / write request for the data from the higher-level device, and the remote storage controller While excluding the read / write request from the host device, the data is stored in the subordinate storage medium, and the data write request is issued to the remote storage control device, and the storage under the remote storage control device is performed. After storing the data in the medium, the upper-level device issues a request to release the exclusion of the read / write of the data from the higher-level device to the remote storage controller. A remote file sharing system wherein data consistency is assured by a device, and data which is remotely double-written between the primary and secondary storage controllers can be shared from the primary and secondary host devices. 2. The primary and secondary storage control device according to claim 1, wherein the primary and secondary storage control devices include a table for storing information for exclusion of reading / writing of shared data from a higher-level device, and a storage remote from the storage control device. When an exclusive request for a read / write request from the higher-level device is issued to the control device, the remote storage control device stores the data that excludes the read / write request from the higher-level device in a table storing the subordinate exclusive information. The position information is stored, and the data read / write request from the higher-level device is used to exclude the data read / write request from the higher-level device when the position information of the data is stored in the table.
Report to the higher-level device that issued the request that processing cannot be performed,
When the position information of the data is not stored in the table, by receiving a data read / write request from the higher-level device, the data that has been remotely double-written between the primary and secondary storage controllers is shared from the primary and secondary higher-level devices. A remote file sharing system characterized in that it can be used. 3. The remote file sharing system according to claim 2, wherein the primary storage control device includes: a transmission control circuit for issuing a data read / write request to the secondary storage control device; The secondary storage controller includes a reception control circuit for receiving a data read / write request to the control device.The secondary storage control device also includes a transmission control circuit for issuing a data read / write request to the primary storage control device. A reception control circuit for receiving a data read / write request from the control device to the secondary storage control device is provided.The transmission control circuit and the reception control circuit are connected to each other, and the path is configured to transfer the request and the data. A remote file sharing system and a storage controller. 4. The remote file sharing system according to claim 2, wherein the primary storage controller issues a read / write request to the secondary storage controller and the read / write request issued from the secondary storage controller. It has a transmission / reception control circuit for performing control for receiving, and also for the secondary storage control device, a control for issuing a read / write request to the primary storage control device, and for receiving a read / write request issued from the primary storage control device. A remote file sharing system and a storage, comprising: a transmission / reception control circuit for performing control for connecting the transmission / reception circuits under the primary and secondary storage control devices, and comprising a path for bidirectionally transferring the request and data. Control device.