JPH0354650A - Data check system for double write electronic disk - Google Patents

Abstract

PURPOSE:To surely secure the coincidence of data for double write by performing the save operation in one electronic disk device and performing comparison and check of saved data in the other. CONSTITUTION:An electronic disk device A 1 and an electronic disk device B 2 pair off for double write, and the same data is stored there, and the electronic disk device A 1 executes saving and the electronic disk device B 2 compares and checks data. The electronic disk device A 1 starts the saving operation by an interface signal group 51. Meanwhile, the electronic disk device B 2 seizes a magnetic disk device 3 by an interface signal group 52 some time after the occurrence of the saving operation factor and reads out data saved in the magnetic disk device 3 after seizing and compares it with data in the device itself to check data. Thus, coincidence of data is surely secured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a data check method for dual-write electronic disks, and in particular to data check using a save disk. Conventional technology Conventionally, in this type of data check method, each dual-write electronic disk unit (ECU) is connected to a magnetic disk unit (SVD).
), the saved data is read again and checked to see if it matches the original data, and there is no check to see if the data matches between dual-write electronic disk devices. There wasn't. Figure 2 shows an example of the configuration of the conventional technology. In FIG. 2, 11.12 indicates an electronic disk device, and 13.14 indicates a magnetic disk device. Problems to be Solved by the Invention In the conventional dual-write electronic disk data check method described above, each electronic disk device checks the data saved on the magnetic disk device. The drawback is that data consistency between electronic disk devices cannot be guaranteed because no checks are performed between them. The present invention has been made in view of the above-mentioned conventional situation,
Therefore, an object of the present invention is to provide a new data check method for dual-write electronic disk devices that eliminates the above-mentioned drawbacks inherent in the conventional technology and that makes it possible to reliably guarantee data consistency between electronic disk devices. The purpose is to provide. Means for Solving the Problems In order to achieve the above object, the data check method for dual-write electronic disks according to the present invention is based on two electronic disk devices in which the same data is written, and A magnetic disk device for saving data of the electronic disk device cross-call connected to the electronic disk device, and one of the two electronic disk devices when it is necessary to save data from the electronic disk device to the magnetic disk device. After one electronic disk device saves data to the magnetic disk device, the other electronic disk device reads out the data saved in the magnetic disk device, compares it with the data of its own device, and checks the data, and if a discrepancy is detected, the nonvolatile storage unit and a means for remembering that there was a discrepancy. Embodiment Next, a preferred embodiment of the present invention will be specifically explained with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. Referring to FIG. 1, the electronic disk device (A) 1 and the electronic disk device (B) 2 form a dual-write pair and store exactly the same data. Here, electronic disk device (
It is assumed that A) 1 executes the save and electronic disk device (B) 2 performs the data check conveyor. When it becomes necessary to save data in the electronic disk device due to a power-off or power outage, etc., the electronic disk device (A) 1 seizes (captures) the magnetic disk device 3 by the interface signal group 51, and saves the data of the own device. Start the save operation. When the save operation is finished, the electronic disk is loaded! (A) 1 releases the magnetic disk device 3. On the other hand, the electronic disk device (B) 2 seizes the magnetic disk device 13 by the interface signal group 52 some time after the save operation factor occurs and enters the reserve state B (t child disk device (A>1 is in the save operation)). If so, the magnetic disk device 3 is the electronic disk device (A) 1
The seeding operation is repeated until it is released. however,
Electronic disk device (A) 1 and electronic disk device (B) 2
This is not necessary if the electronic disk device (A) 1 has a communication function, and the electronic disk device (B) 2 only needs to start the seeding operation after being notified from the electronic disk device (A) 1 that the save operation has ended. After seeding the magnetic disk unit 3, the disk unit W (B) 2 reads the data saved in the magnetic disk unit if3 and compares it with the data of its own device.If there is a discrepancy after the comparison check, the electronic disk unit (B) )2 records the mismatch in the control area of the magnetic disk device 3, and if they match, the process ends without recording anything.Here, the data save unused area of the magnetic disk device 3 is used in the non-volatile storage section, This area is called the control area.The next time the power is turned on, the electronic disk drive 1f(A)1 and the electronic disk drive (B>2) will control the magnetic disk drive rIl.
3 is read, and if a discrepancy is recorded, the host device (not shown) is notified. If no discrepancy is recorded, each electronic disk device 1 and 2 restores the data in the magnetic disk device 3, and each electronic disk device is placed in ready status G (status B that can be accessed from the host device). becomes. Furthermore, in the case of an electronic disk device that has a memory backup function, the storage process is not necessary and the device is in a ready state. Effects of the Invention As explained above, according to the present invention, a magnetic disk device is connected by a cross-call connection to two electronic disk devices in which the same data is written, and a save operation is performed from one electronic disk device. By performing a comparison check with the saved data on the other electronic disk device, it is possible to reliably guarantee data consistency as dual writing.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention. 1...Electronic disk unit iT (EDU(A)), 2
...Electronic disk device (EDLI (B)), 3...
・Magnetic disk device (SVD), 51.52...
Interface Signal Group FIG. 2 is a block diagram showing an example of the configuration of the conventional technology.

Claims (1)

[Claims] It consists of two electronic disk devices in which the same data is written, and a magnetic disk device for data saving of the electronic disk device that is cross-call connected to the two electronic disk devices, and the data is saved from the electronic disk device to the electronic disk device. When it becomes necessary to save data to a magnetic disk device, one of the two electronic disk devices saves the data to the magnetic disk device, and then the other electronic disk device saves the data to the magnetic disk device. A data check method for a dual-write electronic disk characterized by having a means for reading out the data and comparing it with the data of the own device, and storing the fact that there is a mismatch in a non-volatile storage section when a mismatch is detected. .