JPH04369711A - Electronic disk sub-system - Google Patents

Abstract

PURPOSE:To keep the high reliability of data without deteriorating performance. CONSTITUTION:A first electronic disk device 100, a second electronic disk device 200 and a third electronic disk device 300, into which the same data is written, are daisy-chain-connected by a processor and a first interface 400, and the second electronic disk device and the third electronic disk device are connected by a second interface 500. The respective electronic disk devices 100, 200 and 300 have first comparator circuits 102, 202 and 302 comparing the data transmitted from the first interface 400 with the data on a device in use and second comparison circuits 104, 204 and 304 comparing the data transmitted from the second interface 500 with the data on the device in use.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic disk device used in an information processing apparatus, and more particularly to checking data written in triplicate.

0002

2. Description of the Related Art Conventionally, in this type of electronic disk subsystem, in order to compare data of three electronic disk devices in which the same data is written, data is read from each electronic disk device using software. Comparisons were made using software.

0003

In the conventional electronic disk subsystem described above, since data is read from each electronic disk device using software, the reading process must be performed at least three times. Furthermore, since the comparison is also performed by software, there is a problem in that the load on the software increases and the performance of the system decreases significantly.

0004

[Means for Solving the Problems] In an electronic disk subsystem of the present invention, a first electronic disk device, a second electronic disk device, and a third electronic disk device in which the same data is written are processing devices. and a first interface, the second electronic disk device and the third electronic disk device are connected by the second interface, and each electronic disk device receives the data sent from the first interface. a first comparison circuit that compares the data sent from the second interface with data of the own device; and a second comparison circuit that compares the data sent from the second interface with the data of the own device; When reading data from the electronic disk device, the data read from the first electronic disk device is sent to the second electronic disk device and the third electronic disk device through the first interface. A first comparison circuit compares data, and the data read from the second electronic disk device is transferred to the second electronic disk device of the third electronic disk device through the second interface.
The data comparison circuit is characterized in that data is compared using a comparison circuit.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

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

In FIG. 1, a processing device, a first electronic disk device 100, a second electronic disk device 200, and a third electronic disk device
The electronic disk device 300 is connected to the first
are connected by an interface signal group 400. Further, the first electronic disk device 100, the second electronic disk device 200, and the third electronic disk device 300 are also connected by a second interface signal group 500 in a daisy chain connection.

The reason why the first electronic disk device 100 is connected to the second interface signal group is in case the operation of the device is changed due to a failure or the like.

The first electronic disk device 100 includes a memory section 106 for storing data, and a memory section 106 for storing data.
A read buffer 105 that temporarily stores data, a write buffer 101 that temporarily stores data sent from the first interface signal group 400, and a write buffer 101 that temporarily stores data sent from the second interface signal group 500. A first comparison circuit 102 compares the data in the write buffer 101 and the data in the read buffer 105, and a second comparison circuit compares the data in the write buffer 103 and the read buffer 105. Comparison circuit 104
have. Further, the second electronic disk device 200 and the third electronic disk device 300 have a similar configuration.

Next, the operation will be explained.

When writing data, in the first electronic disk device 100, the data sent from the first interface 400 passes through the write buffer 101 and is stored in the memory section 106.
written to. At the same time, the second electronic disk device 2
00 and the third electronic disk device 300 in the same manner.

When reading data, the read buffer 1 is read from the memory section 106 of the first electronic disk device 100.
05, the data is sent to the processing device through the first interface signal group 400, and is written into the write buffer 201 of the second electronic disk device 200 and the write buffer 301 of the third electronic disk device 300.

In the second electronic disk device, the memory section 2
The first comparison circuit 202 compares the data read from 06 through the read buffer 205 and the data in the write buffer 201. Furthermore, data that is compared simultaneously with the read buffer 205 of the second electronic disk device 200 passes through the second interface signal group 500 and is sent to the write buffer 303 of the third electronic disk device 300.
written to.

In the third electronic disk device 300, when data exists in both the write buffer 301 and the write buffer 303, the data is transferred from the memory section 306 to the read buffer 3.
The first comparison circuit 302 simultaneously compares the data read through 05 with the data in the write buffer 301 and the second comparison circuit 304 compares the data with the data in the write buffer 303.

As a result, all of the comparison results of the first comparison circuit 202, the first comparison circuit 302, and the second comparison circuit 304, or the comparison results of the first comparison circuit 202 and the first comparison circuit 302
If either one of these is correct, it is assumed that the data in the first electronic disk device 100 is correct, and the first comparator circuit 2
When only 02 matches, it is assumed that the data of the third electronic disk device is defective, and when only the first comparison circuit 302 matches, it is assumed that the data of the second electronic disk device 200 is defective. Further, if only the comparison result of the second comparison circuit 304 matches, the first electronic disk device 10
Assuming that the data of 0 is defective, the process is changed so that the data in the memory section 206 of the second electronic disk device 200 is sent to the processing device via the first interface signal group 400.

Furthermore, if the results of all comparison circuits do not match, it is assumed that there is no normal data and an error is reported to the processing device. If the first electronic disk device 100 stops functioning due to a failure or the like, the data of the second electronic disk device 200 is sent to the processing device, and the third electronic disk device 300 compares the data.

[0017]

Effects of the Invention As explained above, the electronic disk subsystem of the present invention operates while comparing the data of three electronic disk devices with each other in a single read operation, so that the electronic disk subsystem of the present invention operates while comparing the data of three electronic disk devices with each other in a single read operation. High reliability can be obtained.

[Brief explanation of the drawing]

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

[Explanation of symbols]

101, 103, 201, 203, 301, 303
write buffer

Claims (1)

[Claims] 1. A first electronic disk device, a second electronic disk device, and a third electronic disk device in which the same data is written are daisy-chain connected to a processing device by a first interface, and The electronic disk device and the third electronic disk device are connected by a second interface, and each electronic disk device compares the data sent from the first interface with the data of its own device. and a second comparison circuit that compares the data sent from the second interface with the data of the own device, and when the processing device reads data from the electronic disk device, the first The data read from the electronic disk device is passed through the first interface, the data is compared by the first comparing circuit of each of the second electronic disk device and the third electronic disk device, and the data is compared with the data read from the electronic disk device. The data read from the second electronic disk device is transmitted to the second electronic disk device of the third electronic disk device through the second interface.
An electronic disk subsystem characterized by comparing data using a comparison circuit.