JPH0581142A - Electronic equipment - Google Patents

Abstract

PURPOSE:To suppress the degradation of a processing speed by the duplex of data to minimum by making at least two sets of hard disk device store only necessary data every unit of file at a low cost by duplicating it. CONSTITUTION:A first hard disk device and a second hard disk device connected by a daisy chain are provided and a file name table storing the file name controlling data to be duplicated is provided. The data controlled by the file name stored in the file name table is stored in the first disk device and the second hard disk device by duplicating it. When an error occurs at the time of the reading from the first hard disk, the reading of the data is performed from the second hard disk.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electronic equipment having a plurality of external storage devices.

[0002]

2. Description of the Related Art In electronic equipment such as POS (Point of Sales) terminal devices, hard disk devices are generally used as external data storage devices. Further, in that hard disk device, important data may be stored, and in order not to lose the data due to a failure of the hard disk device, two hard disk devices are provided, and each of the two hard disks has the same data. By duplicating the data that stores the data of
Even if one hard disk fails, important data is not lost.

As a method for duplicating data in two hard disk devices, firstly, when a CPU (central processing unit) of an electronic device controls writing in one hard disk device, another hard disk is automatically operated. Data is also stored in the device as hardware (mechanism / device) (mirrored). In this case, such special hardware needs to be equipped separately from the hard disk device.

However, this hardware that duplicates data by two hard disk devices is a special hardware (mechanism, mechanism, separate from the two hard disk devices).
Since it is necessary to equip the device), there is a problem that the whole system becomes large and the cost becomes high.

Therefore, as a method of duplicating data by two hard disk devices not by hardware but by software, two hard disk devices are connected in a daisy chain in two, one is O
One that incorporates data duplication processing into the basic program that controls the S (operating system) hard disk drive, and another that incorporates data duplication processing into the application programs used in actual work. There is.

[0006]

However, even in the case of using software, if the data duplication processing is incorporated into the basic program for controlling the hard disk drive of the former OS, the CPU will be Since the data is duplicated, all the data must be written in the two hard disk devices, and the processing speed of the electronic device decreases.

In the latter application program that incorporates data duplication processing, only the required data can be duplicated on a file-by-file basis, so the reduction in processing speed due to data duplication can be minimized. Since the processing of data duplication must be incorporated into the required application program,
There is a problem that it takes time and cost to develop such an application program.

Therefore, according to the present invention, only the data required for each file unit can be redundantly stored in at least two hard disk devices at a low cost, and the decrease in processing speed due to the duplication of data can be minimized. The purpose is to provide an electronic device.

[0009]

According to the present invention, there is provided a central processing means, and a plurality of external storage devices for reading and writing data based on instructions for reading and writing predetermined data by the central processing means. And a data management name storage unit that stores a data management name that manages data to be redundantly stored in a plurality of external storage devices, and a central processing unit that reads or writes data from or to the external storage device. Is instructed, the duplication file judgment means for judging whether or not the data management name for managing the data is stored in the data management name storage means, and the data management name for managing the data by this duplication file judgment means. When it is determined that the data is stored in the data management name storage means, the central processing means instructs writing of data. In the case where the data cannot be read from the first external storage device when the central processing means gives an instruction to read the data, the duplicate writing control device stores the data in a plurality of external storage devices in duplicate. ,
An auxiliary reading control means for reading data from another external storage device is provided.

[0010]

In the present invention having such a configuration, the data management name storage means stores the data management name for managing the data to be redundantly stored in the plurality of external storage devices.

When the central processing means instructs the external storage device to read or write the data, the duplicate file determination means determines whether or not the data management name for managing the data is stored in the data management name storage means. Is determined.

When it is judged by the duplicate file judging means that the data management name for managing the data is stored in the data management name storing means, when the central processing means gives an instruction to write the data, The data is redundantly stored in a plurality of external storage devices by the duplicate writing control means, and when the central processing means gives an instruction to read the data and the data cannot be read from the first external storage device, The data is read from another external storage device by the auxiliary reading control means.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a POS (Point of Sales) terminal device.
In the figure, 1 is a CPU (central processing unit) that constitutes the main body of the control unit.

A ROM (Read Only Memory) 2 in which program data for processing performed by the CPU is stored,
A RAM memory board 3 in which areas of various memories used when the CPU 1 performs processing are formed and a file name table 3a as a data management name storing means is formed, a clock circuit 4 for outputting time data, a floppy disk. FDD (floppy disk device) controller 6 to which the device 5 is connected, communication I / F (interface) 7 connected to the host computer via a line
Are connected to the CPU 1 via a system bus 8.

Keyboard 9 and display (CRT) 1
Keyboard controller 11, CRT controller 12 and printer controller 13 for controlling the printer 0 and the printer respectively, and the CPU via the system bus 8.
It is connected to 1.

A first hard disk device (1-HDD) 15 and a daisy chain 16 as external storage devices.
HDD for controlling together with a second hard disk device (2-HDD) 17 as an external storage device connected by
The controller 18 is also connected to the CPU 1 via the system bus 8. FIG. 2 shows the flow of the hard disk driver processing performed by the CPU 1. First, initial processing for initializing various memories and interfaces is performed.

Next, in step 1, a process of accepting a command input by the host computer or the keyboard 9 or a command of an application program is performed. Then, it is determined whether the received command is a file designation command, a write command, or a read command. If neither of these is the case, the process returns to the command receiving process of step 1 again.

If the received command is a file designation command, the data of the file name (data management name) supplied following the file designation command is stored in the file name table 3a formed on the RAM memory board 3 ( Register). When the data of this file name is stored in the file name table 3a, the process is returned to the command receiving process of step 1 again.

If the received command is a write command, the data designated by the write command is written to the first hard disk device 15, and the file name (data management name) for managing the data is set. It is determined whether or not the file is stored in the file name table 3a (duplicated file) (duplicated file determination means). The file name that manages the data is the file name table 3a.
If it is not stored in the command reception process, the process is returned to the command reception process of step 1 again. If the file name for managing the data is stored in the file name table 3a (if it is a duplicated file), the data is written to the second hard disk device 17 (duplication writing control means). The process is returned to the command receiving process of step 1 again.

Further, if the received command is a read command, the data specified by the read command is read from the first hard disk device and the read data is requested (eg RAM memory board 3).
Send to. Here, it is confirmed whether or not an error related to reading has occurred, and if no error has occurred, the process returns to the command acceptance processing of step 1 again. If an error has occurred, it is determined whether the file name for managing the data designated by the read command is stored in the file name table (duplicated file) (duplicated file determination means). If the file name for managing the data is not stored in the file name table 3a, error status processing is performed, and the file name for managing the data is stored in the file name table 3a. If it is a duplicated file, the data is read from the second hard disk device (auxiliary reading control means) and the read data is transmitted to the request destination. Here again, it is confirmed whether or not an error related to reading has occurred, and if no error has occurred, the process returns to the command acceptance processing of step 1 again. If an error has occurred, error status processing is performed.

In this embodiment having such a configuration, first, a file name command is used to register a file name for managing duplicated data in the file name table 3a.

A command for writing to the hard disk device,
That is, when the write command is output, the first hard disk device 15 of the data specified by the write command is output.
If the file name for managing the data is registered in the file name table, the data is also written to the second hard disk device 17. In this way, the data managed by the file name registered in the file name table 3a is redundantly stored and duplicated in the first hard disk device 15 and the second hard disk device 17.

When a read command to the hard disk device, that is, a read command is output, the first
The data designated by the read command is read from the hard disk device 15 and the read data is transmitted to the request destination. If a reading error etc. occurs here,
It is determined whether the file name that manages the data designated by the read command is registered in the file name table 3a. If the file name that manages the data is not registered in the file name table 3a, the file name is unchanged. If the error status processing in which processing such as transmission of read error information is performed and the file name that manages the data is registered in the file name table 3a, the second
The data designated by the read command is read from the hard disk device 17 and the read data is transmitted to the request destination. Also in this case, if a read error occurs, the error status process is performed in which the read error information is transmitted.

As described above, according to the present embodiment, when the data is duplicated by the two hard disk devices, the file name table 3a for storing the file for managing the data to be duplicated is provided, and the data to be written or read is provided. By checking whether the file name for managing the file is stored in the file name table 3a, only the data managed by the file name registered in the file name table 3a is stored in the first hard disk device 15 and the second hard disk device 17. The data can be stored redundantly and the data can be duplicated.

Further, there is no need to develop special hardware or application programs, and the second hard disk device is simply connected by a daisy chain, and the file name for managing the data to be duplicated is stored in the file name table 3a. Since it only needs to be done, it is possible to easily build a system that duplicates only the necessary data in a short time and at low cost.

Moreover, since only the data managed by the file name registered in the file name table 3a is duplicated and redundantly stored in the first hard disk device 15 and the second hard disk device 17, the processing speed is reduced. You can minimize the decline.

In this embodiment, the data stored in the two hard disk devices is determined by the file name as the data management name, but the present invention is not limited to the file name. It is also possible to judge the data duplicated in the two hard disk devices based on the directory name or the like.

Further, in this embodiment, the case where the data is redundantly stored in the two hard disk devices has been described, but the present invention is not limited to the two hard disk devices, and three or more hard disk devices. It is also applied to the case where the data is stored in duplicate.

[0029]

As described in detail above, according to the present invention,
Only the required data can be redundantly stored in at least two hard disk devices for each file unit at low cost, and it is possible to provide an electronic device in which the reduction in processing speed due to the duplication of data is minimized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of essential parts of an embodiment of the present invention.

FIG. 2 is a diagram showing a flow of hard disk driver processing of the embodiment.

[Explanation of symbols]

1 ... CPU, 3a ... File name table, 15 ... First hard disk device, 16 ... Daisy chain, 17 ...
Second hard disk device.

Claims (1)

[Claims] 1. An electronic device comprising a plurality of external storage devices, which is provided with a central processing means, and in which the data is read and written based on instructions of reading and writing of predetermined data by the central processing means, Data management name storage means for storing a data management name for managing data to be redundantly stored in a plurality of external storage devices, and when the central processing means instructs the external storage device to read or write data. A duplicate file determining means for determining whether or not a data management name for managing the data is stored in the data management name storage means, and a data management name for managing the data by the duplicate file determining means is the data When it is determined that the data is stored in the management name storage means, the central processing means writes the data. Overwriting control means for storing the data redundantly in the plurality of external storage devices when instructed, and the data from the first external storage device when the central processing means instructed to read the data. And an auxiliary reading control means for reading the data from another external storage device when the electronic device cannot be read.