JPS6367669A - Control system for storage controller - Google Patents

Abstract

PURPOSE:To produce an access start request through a computer without waiting even in a copying mode by connecting a shared memory device with an interface exclusive for copying and inhibiting a read access to the shared memory device that is copied in a copying mode to attain other accesses. CONSTITUTION:When an access start request given from a computer 1 requires a writing action, a flag is neglected and access start request signals 22a and 22c are selected by the access start request selection means 10a and 10b of master and slave systems respectively. Then address/data control signals 21a and 21c are selected from the outputs of means 10a and 10b by interface selection means 9a and 9b and written to memory parts 12a and 12b respectively. Thus it is possible to execute an access start request given from a computer with virtually no wait even in a copying mode.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control system for a storage control device of a computer system that requires high reliability.

[Conventional technology]

FIG. 3 is a block diagram showing the hardware configuration of a conventional duplex shared storage control device. In the figure, 1.2 is a computer, 3 and 4 are shared storage devices, 5 is dedicated transcription hardware, 6a to 6c, 7a to 7c are interfaces.

Next, the operation will be explained. Conventionally, in order to realize reliable computer systems, a method of duplicating shared storage devices has often been adopted. In order to duplicate storage devices, the memory contents of the duplicated shared storage devices must be the same, and the accessing computer must write the same contents to the duplicated shared storage devices and read them from the duplicated shared storage devices. There is a need for a means of checking content consistency, as well as a means of transferring the content of one system to the other system. This occurs when only one system is operating due to a failure, and when the failure is repaired and the system is returned to redundant operation, or when starting up the system, the contents of one system are transferred to the other system. This is because the contents need to be consistent. There are the following methods for transferring the storage contents between the duplex shared storage devices.

This is a method in which dedicated hardware is provided to perform the transfer operation between the duplexed shared storage devices, and the transfer is performed between the duplexed shared storage devices. In Figure 3, a normal calculator 1,
The access request from 2 is sent to the shared storage device 3 from the interfaces 5a and 5b, and to the shared storage device 4 from the interfaces 7a and 7b, where reading and writing are performed. Assuming that all co-existing storage devices 4 have stopped operating for some reason,
Next, in order to start operation as a duplexed shared storage device, it is necessary to transfer the contents of the shared storage device 3 to the shared storage device 4. For transcription, access requests from the computer 1.2 are prohibited, and a read access request for address α from the hardware 5 dedicated to transcription is sent from the interface 6C to the shared storage device 3.
The contents of address α of the shared storage device 3 are read out and sent to the transfer dedicated hardware 5 via the interface 6C. Next, the transfer dedicated hardware 5 sends a write access request to the α address to the shared storage device 4 through the interface 7c, and the contents of the α address of the shared storage device 3 are written to the α address of the shared storage device 4. By performing the transfer operation from address 0 to the maximum address of the installed shared storage devices in this manner, the contents of the duplicated shared storage devices can be matched.

[Problem that the invention seeks to solve]

Since the conventional duplex shared storage control device is configured as described above, depending on the storage capacity of the shared storage device, for example, if it is 2M words, it will take several hundred to several thousand milliseconds.
During this time, access requests from computers are prohibited, which has the disadvantage that it cannot be used in computer systems that require online processing.

The purpose of this invention is to obtain a duplex shared storage control device which can be accessed from a computer during transcription, can be used in a computer system that requires online processing, and has high responsiveness and high multiplicity. .

[Means for solving problems]

The storage control device according to the present invention enables the transfer of information between shared storage devices, sets a flag for the shared storage device to which the information has been transferred, and performs read operations for the shared storage device to which this flag is set.

Among write accesses, only read accesses are prohibited, and other accesses are allowed to be executed.

[Effect]

Read access is prohibited to the shared storage device in the process of being transferred, but read access is permitted to other shared storage devices. Also, write access is possible to both shared storage devices.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to the drawings. In Figure 1, 1.2 is a computer, 3.4 is a shared storage device, 6a, 6
b and? a and 7b are computer-shared storage device interfaces, and 8 is a shared storage device interface. Second
The figure shows a specific example of the shared storage devices 3 and 4 in FIG. 1, in which 9a and 9b are interface selection means, 10a and 10b are access activation request selection means, and
．． 11b is a transfer operation control means; 12a;

12b is a storage unit, 21a to 21b are computer-shared storage device interface signals, 22a to 22d are access activation request signals from the computer, and 23a.

Reference numeral 23b represents an access activation request signal from a shared storage device of another system, 24a and 24b are inter-shared storage device interface signals, and 25a and 25b are internal interfaces exclusively for reading from the transfer operation control means to the storage unit.

Next, the transfer operation is performed from the shared storage device 3 to the shared storage device 4.
We will explain the case where it is executed towards. In this case, if the former is the main system and the latter is the slave coexisting storage device, the transfer operation control means 11a of the main system sends a signal to the slave system to start the transfer operation through the inter-shared storage device ink interface 8. It will be done.

When the slave transfer operation control means 11b receives this signal, it sets a register (not shown) indicating that the transfer operation is in progress.
Set. That is, a flag is set. If this register is set, read requests among access requests from the computer will be ignored. Assuming that the transfer operation is now being performed at address α, the transfer operation control means 11a of the main system reads the contents of address α of the main system during the first half of the transfer operation, and transfers addresses, data, and control signals between the shared storage devices. It is sent to the subordinate shared storage device 4 through the interface 8. In the slave shared storage device 4, the access activation request signal 23a from the primary system is selected by the access activation request selection means 10b, and the address and data from the primary system are selected by the interface selection means 9b based on the output of the access activation request selection means 10b.

It receives the control signal and writes its contents to address α in the storage section 12b. This transfer operation is executed from address O of the main system to the maximum address of the shared storage device. When the transfer operation is executed up to the maximum address, a transfer operation end signal is sent from the transfer operation control means 11a of the main system to the transfer operation control means 11b of the slave system. When the slave transfer operation control means 11b receives this end signal, it resets a register (not shown) indicating that the transfer operation is in progress. Next, a case will be described in which an access activation request signal is sent from a computer during a transfer operation. Assuming that the access activation request signal is sent from the computer 1, if this access activation request is a read request, the slave shared storage device 4 has a flag set indicating that it is in the process of transferring. A read operation is not executed from the slave system, but only from the main system. The operation is main system access activation request selection means 1
From the output of the access activation request selection means 10a, the interface selection means 9a selects the address and control signal 21a from the calculation m1, and executes the read operation from the storage section 12a. .

If the access activation request from the calculation ml is a write request, the above flag is ignored and the access is sent to the main system.

The access activation request signals 22a and 22c are selected from the access activation request selection means 10a and 10b of the slave system, and the address, data, and control signals 21a and 21c are selected from the interface selection means 9a and 9b based on the output of the access activation request selection means 10a and 10b. is selected, and a write operation is executed to the storage units 12a and 12b. Next, an access activation request from a computer when a transfer operation is not in progress corresponds to a write request during a transfer operation. It goes without saying that even if the main system and slave system of the transfer operation are reversed, the same operation will occur. Therefore, even during the transfer operation, it is possible to execute the access activation request from the computer without having to wait for it.

Although the description has been made assuming that there are two computers and two co-existing storage devices, the present invention can be similarly applied even if more than two computers and co-located storage devices are provided.

〔Effect of the invention〕

As described above, according to the present invention, a shared storage device is connected through an interface dedicated to transcription, and during transcription, read access to the shared storage device being transcribed is prohibited, while other accesses are enabled. It is possible to provide a duplex shared storage device that can execute an access activation request from a computer almost without waiting even during operation, and can also be used in a computer system that performs online processing.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a control system for a storage control device according to an embodiment of the present invention. FIG. 2 shows a specific example of the configuration of the shared storage device shown in FIG. FIG. 3 is a block diagram of a duplex shared storage device according to an example of the conventional art. 1.2 is a computer, 3 and 4 are shared storage devices, 5 is dedicated transcription hardware, 6 and 7 are computer-shared storage device interfaces, 8 is a shared storage device interface, 9 is an interface selection means, and 10 is an access device. 11 is a transfer operation control means, and 12 is a storage section. Agent: Masuo Oiwa (and 2 others) Ka3 figure procedural amendment (voluntary) 28 Invention title j'5J + damage placement prevention type 3, person making the amendment 5, ? ! Positive claims and detailed description of the invention. 6. Contents of amendment (1) The scope of claims will be amended as shown in the attached sheet. (2) In the 9th and 14th lines of page 4 of the specification, the words ``sent out'' should be corrected to ``sent out''. (3) From the 20th line of page 6 to the 2nd line of page 7 of the same book, ``Face signal, . . . interface.j'' is corrected to ``Face signal.'' (4) In the fourth line of page 7 of the same book, the phrase "towards storage device 4" is amended to read "toward storage device 4." (5) In the 20th line of page 6 of the same book, the phrase ``When this end signal is received'' is corrected to ``When this end signal is received.'' Above 2, Claim (1) No. 1. The first. which is accessible by both the second computer. In the control method of a storage control device including a second shared storage device, the first. Second shared note ↑, indicates that the α devices are connected by an interface dedicated to transcription, information can be transferred between both shared storage devices, and that information is being transferred to the other shared storage device during transcription. Set the flag, 1st. When there is a read access activation request from either of the second computers to both shared storage devices, information is read only from the one shared storage device for which the above flag is not set, and write access is activated. When a request is made, the above flag is ignored and both shared notes 1. α
A control method for a storage control device, characterized in that information is written to a storage device. (2) Interface selection means for selecting either the interface from the other shared storage device t, a, the interface from the first computer, or the interface from the second computer; 1. Each shared storage means is provided with an access activation request selection means for receiving one of the access activation request signals of each of the second computers, and a transfer operation control means for controlling the interface selection means and the access activation request selection means. A control method of the control device described in 1 and 9 below.

Claims (2)

[Claims] (1) In a control method for a storage control device equipped with first and second shared storage devices that can be accessed by both the first and second computers, an interface dedicated to transfer is used between the first and second shared storage devices. connection, enable the transfer of information between both shared storage devices, and set a flag indicating that information is being transferred to the other shared storage device during the transfer, from either the first or second computer. When there is a read access activation request for both shared storage devices, information is read from only one of the shared storage devices for which the above flag is not set, and when there is a write access activation request, the above flag is set. 1. A control method for a storage control device, characterized in that information is written to both shared storage devices while ignoring. (2) Interface selection means for selecting either the interface from the other shared storage device, the interface from the first computer, or the interface from the second computer, and the other shared storage device and the first and second computers. Each shared storage means is provided with an access activation request selection means for receiving one of the access activation request signals, and a transfer operation control means for controlling the interface selection means and the access activation request selection means. A control method for storage control devices.