JPS6053326B2 - Double data recording method for input/output control equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an input/output control device that controls data transfer between a line control device connected to a line and a file memory device based on instructions from a central control system of a computer. This invention relates to a method of double recording in a file memory device.

When data received by a line control device is stored in a file memory device for a long time, the data is often recorded twice in consideration of the reliability of the file memory device.

There are two ways to do this: the input/output controller transfers data between the line controller and the file memory device twice, and the other is to transfer data from the line controller to the input/output controller once and then transfer the data to the file memory device. There is a method of transferring data twice, but the latter method is superior in terms of high throughput. FIG. 1 is an explanatory diagram of a conventional method in which data is transferred twice to a file memory device in one data transfer from the line control device.

In FIG. 1, 1 is a central control device, 2 is an input/output control device, 2-1 to 2-n are multi-sided data buffers of a certain size provided in the input/output control device 2, and 3 is an input/output control device. A line control device 4-1 to 4-m has a built-in buffer memory composed of a random access memory or the like, and 4-1 to 4-m are file memory devices such as magnetic disk devices. The input/output control device 2 starts up the line control device 3 according to instructions from the central control device 1, and transfers data from the line control device 3 to a designated data buffer (2-1) in 2-1 to 2-n. Transfer and accumulate. Thereafter, the input/output control device 2 starts the first file memory device (referred to as 4-1), and when it becomes accessible, writes the data in the data buffer 2-1 to the file memory device 4-1. After that is completed, start the second file memory device (referred to as 4-2) and
When it becomes accessible, the data in the data buffer 2-1 is written to the file memory device 4-2. However, in this conventional method, since accesses to the first and second file memory devices that record data in duplicate are processed in series, the processing time is long and the transfer capacity is low.

In order to solve the above conventional drawbacks, the present invention makes access requests to the first and second file memory devices in parallel, transfers data to the file memory device that can be accessed first, and then The same data is transferred to the other file memory device at the same time.The details of the embodiment are described below. Explain.

FIG. 2 shows an embodiment of the present invention, in which 1 is a central controller, 2 is an input/output controller, 2-1 to 2-n are data buffers, 3 is a line controller, 4-1 to 4- m is a file memory device, 5 is a data buffer management table for managing whether data is stored in data buffers 2-1 to 2-n, and 6-1 to 6-m are 4-1 to 4-m. 3 shows subchannel memories that store control information (channel programs) corresponding to each file memory device.

Note that the input/output control device 2 includes the data buffer 2-
In addition to the 1 to 2-n1 data buffer management table 5 and the subchannel memories 6-1 to 6-m, it also controls the interface with the central control device 1, line control device 3, and file memory devices 4-1 to 4-m. Although it is provided with an interface circuit for controlling the input/output control device, a common control section for controlling the operation of each section of the input/output control device, etc., these are omitted in FIG. Hereinafter, data from the line control device 3 is transferred to the data buffer 2-1.
A case will be described in which double recording is performed in the file memory devices 4-1 and 4-2 using the following. Now, the input/output control device 2 first receives first control information from the central control device 1 that instructs data transfer from the line control device 3 to the file memory device 4-1 using the data buffer 2-1, and the data Receives second control information instructing data transfer from the buffer 2-1 to the file memory device 4-2, and stores the first control information in the subchannel memory 6-1'' and the second control information in the subchannel memory 6-1'', respectively. The data is stored in the memory 6-2.

Next, the input/output control device 2 includes a subchannel memory 6-1
The line control device 3 is activated according to the control information, and the data from the line control device 3 is transferred to and stored in the data buffer 2-1, and this fact is registered in the data buffer management table 5. Furthermore, in parallel with this, an access request is issued to the file memory devices 4-1, 4-2 based on the control information of the sub-channel memories 6-1, 6-2. Thereafter, the input/output control device 2 controls the file memory device 4-1.
, 4-2 becomes accessible, the contents of the data buffer management table 5 are read, and if data is stored in the data buffer 2-1, the data is transferred to the file memory device that has become accessible. Write operation is performed. Next, when another file memory device becomes accessible, a second writing operation of the data in the data buffer 2-1 is performed to the file memory device. If data is not stored in the data buffer 2-1, the search is repeated until the data is stored, and when the data is stored in the data buffer, the first write is performed to the file memory device that is accessible at that time. After that, when the other file memory device becomes accessible, a second write is performed to it. In the above explanation, it is assumed that the subchannel memory 6-1 accessing the line control device 3 also accesses the file memory device 4-1 at the same time.
The subchannel memory 6-1 that has accessed the file memory device 4-1 may access the file memory device 4-1 after the data has been stored in the data buffer 2-1.

The operation in this case will be explained below. The input/output control device 2 receives first control information that instructs the central control device 1 to transfer data from the line control device 3 to the file memory device 4-1 using the data buffer 2-1, and the data buffer 2-1.
1 to the file memory device 4-2, and stores them in the subchannel memories 6-1 and 6-2, respectively.

Next, the input/output control device 2 activates the line control device 3 based on the control information in the subchannel memory 6-1, transfers and stores data to the data buffer 2-1, and detects that the data buffer is full. is registered in the data buffer management table 5. Thereafter, the input/output control device 2 uses the control information of the subchannel memory 6-1 to control the file memory device 4-1.
At the same time, an access request is issued to the file memory device 4-2 based on the control information of the subchannel memory 6-2.
Issue an access request to 2. File memory device 4-1,
Writing data to 4-2 is the same as the above method,
Do it for the first one that becomes accessible. All of the above methods are characterized by double recording by accessing two file memory devices in parallel, and the advantages of the present invention are clear when looking at the time charts of FIGS. 3 to 5. be.

Here, FIG. 3 shows the method explained first, FIG. 4 shows the method explained later, and FIG. 5 shows the conventional method. In the figure, T1 is the transfer time with the line control device 3, T2 is the seek and offline search time for the file memory device 4-1, T3 is the transfer time with the file memory device 4-1,
T4 is the seek and offline search time for the file memory device 4-2, T5 is the transfer time with the file memory device 4-2, and T is the holding time. As explained previously, in the method of the present invention, depending on the magnitude relationship of Tl, T2, and T4, the file memory device that has become accessible may wait until data is accumulated in the data buffer. It is shown in Figure 4. However, in the case of waiting, the transfer will start immediately after the data is accumulated in the data buffer. Further, 6-1 and 6-2 are sub-channel memories, and it can be seen that the sub-channel memory 6-1 in FIG. 3 accesses the line control device and the file memory device at the same time. Furthermore, in FIGS. 3 and 4, it can be seen that both the two subchannels operate in parallel. Third
From Figures 5 to 5, it can be seen that while the conventional method performs double recording by serial processing, the method of the present invention performs it by parallel processing, and the method of the present invention has a shorter processing time. It can be seen that the ability and transfer ability are large. As explained above, the present invention is a system in which an input/output control device accesses a file memory device for double recording in parallel in double recording of data; It has the advantage of shortening the time and having a large transfer capacity.

[Brief explanation of the drawing]

Fig. 1 is a block diagram for explaining a conventional data dual recording method, Fig. 2 is a block diagram of an example of the method of the present invention, and Figs. 3 to 5 show the method of the present invention and the conventional method. FIG. 4 is a timing diagram for comparison. DESCRIPTION OF SYMBOLS 1... Central control device, 2... Input/output control device, 2-1 to 2-n... Data buffer, 3... Input/output control device 5 devices, 4-1 to 4-m...・File memory device, 5
...Data buffer management table, 6-1 to 6-m.
...Subchannel memory.

Claims (1)

[Claims] 1 In an input/output control device that controls data transfer between a line control device and a file memory device based on instructions from a central control system, the input/output control device has a data buffer for temporarily storing data, and a data buffer compatible with the file memory device. first control information for instructing data buffers to be used and for instructing data transfer from the line control device to the first file memory device; When second control information instructing data transfer to a second file memory device is given, the first and second control information are respectively stored in subchannel memories corresponding to the designated file memory devices. and stores data from the line control device in the data buffer according to the first control information, and stores data in parallel in the first and second file memory devices according to the first and second control information. The method is characterized in that the data stored in the data buffer is transferred to the first file memory device that can be accessed by issuing an access request, and then the data in the data buffer is transferred to the other file memory device. Data dual recording method for input/output control equipment.