JP2002351746A - Duplex system for hard disk drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a duplex restructuring (copying) time from becoming long each time a hard disk drive is replaced. SOLUTION: This hard-disk-drive duplex system which is so structured as to access both hard disk drives (DISK) for reading and writing can obtain one-disk storage capacity from a one-disk information storage part of a DISK1 which was normal after a DISK2 is replaced and the power source is turned on, rewrite and store other-disk storage capacity stored in an other-disk storage part of the DISK2 into the one-disk storage capacity obtained from the one-disk information storage part, and equalize the storage capacity of a replaced DISK2 and the storage capacity of the DISK1 which was normal to each other to copy all the data stored on the DISK1 to the DISK2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual hard disk drive system constructed so as to access both hard disk drives for reading and writing.

[0002]

2. Description of the Related Art There is known a hard disk drive duplex system constructed to access both hard disks and read / write.

For example, a plurality of electronic cash registers (terminals 1P) disposed in a store shown in FIG. 5 and a store computer (store controller S) capable of data communication with each terminal 1P and forming a higher-level device thereof
C) In the case of the merchandise sales data processing system formed from 10P, a duplex system of a hard disk device is introduced in the server-based store computer 10P.

That is, two hard disk devices 20P, 30P having the same storage capacity in the store computer 10P.
Is provided. Then, the data set and input in the own device (10P) accesses and writes to both the hard disk devices 20P and 30P. Each sales data collected from the terminal (1P) is also written in the hard disk devices 20P and 30P.

[0005] On the other hand, when a product data inquiry is received from the terminal 1P,
P, 30P is accessed to read the product data corresponding to the inquiry (product code), confirm the consistency, and then respond to the terminal 1P. In addition, accurate sales materials can be created by accessing the hard disk devices 20P and 30P and reading and editing the sales data and the like collected and stored.

In such a dual hard disk drive system, for example, one hard disk drive (for example, 20
DISK1) is normal and the other hard disk drive (30P ... DISK2) fails, DISK
Exchange 2

Thus, when the power is turned on after the replacement, the data recovery control means reads the stored data from the normal DISK 1 not to be replaced (ST 50 in FIG. 6) and writes the read data to the DISK 2 (ST 51). Since data is physically copied in sector units, the data recovery for all data is completed if the process is completed for all sectors (YES in ST52). That is, for example, loss of valuable data that cannot be reacquired can be prevented, and data can be saved (backed up) reliably.

[0008]

Nowadays, the capacity and cost of the hard disk drive are remarkably increasing, and at the time of use, the other DIS is replaced in the above-mentioned case at the site of use.
It is feared that the storage capacity of K2 is the same as the storage capacity of DISK2 before replacement. In other words, the storage capacity after replacement (for example, 10 GB) is often larger than the storage capacity (for example, 5 GB) before replacement (in the initially assembled state).

However, in the conventional duplex system, the hard disk drive 20P (30P), that is, DISK1 (D
Since it is sufficient that the data stored and managed in the ISK 2) can be reliably saved (backed up), the DISK 1
It does not make much sense to copy data from one to the other while managing which area is stored in which area in (DISK2). In other words, it is formed so that all the data stored or supposed to be stored in all areas is physically copied (duplex reconstruction) in sector units.

Thus, compared with the case where the storage capacity before replacement and the storage capacity after replacement are the same (for example, 5 GB) and the data duplication reconstruction (copy) time is, for example, 10 minutes, For example, when the storage capacity of the device is increased to 10 GB, the duplex reconstruction (copy) time is 20 minutes. In other words, there is a problem that the double reconstruction (copy) time is cumulatively prolonged as the storage capacity after replacement increases. This will greatly reduce operational efficiency.

An object of the present invention is to provide a hard disk drive capable of preventing a long double rebuilding (copying) time even if the storage capacity after replacement may be larger than the storage capacity before replacement. It is to provide a duplex system.

[0012]

According to the first aspect of the present invention, there is provided a dual hard disk drive system constructed to access both hard disk drives for read / write.

After replacement of the other hard disk device and after power-on, the one disk storage capacity of the one hard disk device can be obtained from the one disk information storage portion of the one hard disk device, and is stored in the other disk information storage portion of the other hard disk device. The other disk storage capacity that is obtained from the one disk information storage unit is replaced with the one disk storage capacity so as to be rewritable, and the storage capacity of the other hard disk drive after replacement and the storage capacity of the normal one hard disk drive are replaced. This is a dual hard disk drive system in which all data stored in one hard disk drive can be copied to the other hard disk drive.

In this invention, when a trouble (abnormality or the like) occurs in the other hard disk drive, the other hard disk drive is replaced with a new hard disk drive. When the power is turned on after the replacement, the one disk storage capacity is obtained from the one disk information storage unit of the normal one hard disk device.

Then, the other disk storage capacity stored in the other disk information storage section of the other hard disk drive after replacement is rewritten and stored in the one disk storage capacity acquired from the one disk information storage section. Thus, it is possible to copy all data stored in the one hard disk drive to the replaced new hard disk drive, assuming that the storage capacity of the other hard disk drive after replacement is the same as the storage capacity of the normal one hard disk drive. it can.

Therefore, when the storage capacity of the replaced hard disk drive is twice as large as the storage capacity of the one hard disk drive, for example, the copy time is twice as long as in the conventional example in which the copy time is doubled. Halved (1
Even if the storage capacity of the other hard disk device is gradually increased thereafter, copying can be performed with the storage capacity of the one (other) hard disk device at the time of device construction, so that the copy time is cumulatively prolonged. do not do.

In other words, even if the storage capacity after the replacement is larger than the storage capacity before the replacement, it is possible to prevent the double reconstruction (copy) time from being prolonged, and
Since the storage capacity conversion can be performed automatically, the management burden on the hard disk can be reduced.

Further, according to the invention of claim 2, after the power is turned on, both of the hard disk devices are accessed to automatically determine which hard disk device is the one hard disk device which was normal and to replace the hard disk device. A hard disk device duplex system formed so as to be able to automatically determine whether the determined storage capacity of the other hard disk device is equal to or larger than the storage capacity of the one hard disk device automatically determined to be normal.

In this invention, when a trouble (abnormality or the like) occurs in the other hard disk drive, the other hard disk drive is replaced. When the power is turned on after this replacement, both hard disk drives are accessed, and it is automatically determined whether one of the hard disk drives is normal (this time non-replacement) and the other is a hard disk drive. Subsequently, the storage capacity of the normal one-side hard disk device is obtained.
Also, it is automatically determined whether or not the storage capacity of the replaced hard disk drive is equal to or greater than the storage capacity of the hard disk drive while it is automatically determined that the storage capacity is normal.

Thus, when it is automatically determined that the storage capacity of the replaced new hard disk drive is equal to or larger than the storage capacity of the normal one hard disk drive, the data is stored in the other disk information storage section of the replaced other hard disk drive. The other disk storage capacity is automatically rewritten and stored in the one disk storage capacity obtained from the one disk information storage unit.

If it is automatically determined that the storage capacity of the other hard disk drive after replacement is not larger than the normal storage capacity of the one hard disk drive (less than the storage capacity), for example, the storage capacity of the other hard disk drive becomes smaller. A warning can be given to the effect that there is a shortage.

Therefore, in addition to providing the same operation and effect as the case of the first aspect of the present invention, it is further possible to determine which one of the normal hard disk drive and the other hard disk drive after replacement and to determine the storage capacity. Since the magnitude discrimination is performed automatically, the duplex rebuilding (copying) can be performed quickly without any trouble, and early restart of the server or the like into which it is introduced can be secured. Even if the hard disk device after replacement has insufficient storage capacity, measures can be taken promptly.

According to a third aspect of the present invention, there is provided a data copying method in which the storage capacity of the replaced other hard disk drive is automatically determined to be normal and the storage capacity of the one hard disk drive is determined not to be larger than the storage capacity of the one hard disk drive. Hard disk drive 2 that is configured to be able to notify that it is not possible
It is a weight system.

In this invention, if it is automatically determined that the storage capacity of the other hard disk drive is not larger than the normal storage capacity of the one hard disk drive after the replacement, the data in the one hard disk drive is copied to the other hard disk drive as it is. When the process is started, an overflow occurs, so that a notification that data copying is not possible is given.

Therefore, in addition to providing the same functions and effects as in the case of the second aspect of the present invention, it is possible to avoid overflow and useless copying work itself.

Further, the invention of claim 4 is a duplex system for a hard disk drive in which the storage capacity of the one hard disk drive is the current storage capacity actually used at that time.

In this invention, the storage capacity of the hard disk drive is not the original (rated) storage capacity but the current current storage capacity actually used at that time. Then, the storage capacity of the other hard disk drive after replacement is rewritten and stored as the current storage capacity of the one hard disk drive. On the other hand, the current storage capacity (for example, 4 GB) of the hard disk device has a smaller value than its original storage capacity (for example, 5 GB).

Therefore, in addition to providing the same operation and effect as in each of the first to third aspects of the present invention, all of the data stored in the normal one hard disk drive is replaced with the other one after the exchange. The data copy time can be further reduced while ensuring that the data is copied to the hard disk device.

Further, the invention according to claim 5 is a duplex system for a hard disk drive in which the data stored in the both hard disk drives is product sales data.

In this invention, the merchandise sales data (for example, setting data for merchandise registration and accounting processing, merchandise file, sales file, etc.) stored in the one hard disk device can be directly copied to the other hard disk device.

Therefore, the hard disk drive can be continuously and smoothly performed while exhibiting the same operation and effects as those of the first to fourth aspects of the present invention, and even in a cashier or the like who does not necessarily have high computer knowledge. Exchangeable and easy to handle.

[0032]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) As shown in FIGS. 1 to 4, the duplex system of the present hard disk device replaces another hard disk device 30 in which trouble (abnormality, etc.) has occurred with a new other hard disk device 30. After the power is turned on, the normal and non-replaced hard disk drive 2
0, the one-disk storage capacity n1 can be obtained from the one-disk information storage section 21. The other-disk storage capacity n2 stored in the other-disk information storage section 31 of the new other hard disk drive 30 can be obtained from the one-disk information storage section
The one hard disk drive 20 is formed so that the storage capacity of the other hard disk drive 30 can be rewritten and stored, and the storage capacity of the normal one hard disk drive 20 is the same as the storage capacity of the normal one hard disk drive 20 (n1). All the stored data can be copied (data duplex reconstruction) to the other hard disk device 30.

The duplex system of the hard disk device of this embodiment is introduced into a store controller (store computer 10) which constitutes a part of a merchandise sales data processing system (POS system). It is formed so that construction can be performed reliably.

In FIG. 1, a server-based store computer (store controller) 10 which forms a part of a merchandise sales data processing system (POS system) together with a plurality of terminals (not shown) includes a CPU 11 and a BIOS.
(ROM) 12, memory (RAM) 13, one hard disk drive (DISK1) and the other hard disk drive (DISK2) connected to a duplex control board 14 constituting a hard disk drive, keyboard 15, display 16, LAN interface 18 and an interface 19 for ISDN.

The LAN interface 18 has LA
A plurality of (for example, 300) terminals (electronic cash registers) not shown are formed so as to be able to perform data communication via N. Each terminal and the store computer 10, which is a higher-level device thereof, jointly execute product sales data processing. Each terminal performs merchandise sales business (product registration business, accounting processing business, etc.) at the sales floor.

The store computer 10 downloads various data (for example, product data) necessary for each terminal to perform the product sales business, responds to inquiries, and executes the product sales business performance data ( For example, sales data is collected from each terminal and managed.

The ISDN interface 19 is connected to an external computer, that is, a host computer in a chain store headquarters and a support computer in a service base so as to be able to perform data communication. This embodiment will be described as a support computer.

Now, on the other hand, a hard disk drive (DISK)
As shown in FIG. 2, the one disk information storage unit 21 in the disk management area 1) stores the type of hard disk, serial number (for example, No. 1), and device name (DISK).
1), the total number of current sectors (for example, m1), the total number of accessible sectors (for example, n1),... Are stored (stored).
Is done.

The current total sector number m1, which indicates the actual operating storage capacity, is smaller than the intrinsic total accessible sector number n1, which is the rated storage capacity.

Similarly, the other hard disk drive (DIS
In the disk management area 31 in the disk management area K2), as shown in FIG.
Serial number (for example, No. 2), device name (DIS
K2), the total number of current sectors (for example, m2), the total number of accessible sectors (for example, n2),... Are stored (stored).

As for the one disk status register 25 of DISK1 (and the other disk status register 35 of DISK2), the bit shown in FIGS.
0 indicates the DISK state (0: normal, 1: abnormal), and bi
t1 represents data load (0: normal load, 1: data abnormal).

The normalization control board 14 operates normally (each bi
At (t0 = 0), both the hard disk devices 20 and 30 are accessed for reading and writing. If a failure has occurred (bit0 = 1), the DISK2 (or DISK)
Do not access 1).

When a failure occurs, the failure occurrence display control means (CPU 11 and BIOS 12) is configured to display an alarm on the display 16 indicating that the DISK 2 has a failure.

In the following, the operator learns from the alarm display on the display 16 that a fault has occurred in the other hard disk drive (DISK2), and replaces the DISK2 with a new one (new).
Will be described with reference to FIG. 4 exemplifying a case where the DISK 2 is replaced with a normal one and the power is turned on again thereafter.

When the power is turned on again, the duplex control board 14 diagnoses one hard disk device (DISK1) according to a command from the control unit (CPU 11 and the like). On the other hand, since bit 0 of the disk status register 25 is “0”,
It is determined to be normal (YES in ST10 of FIG. 4).

If it is determined that a problem has occurred due to some abnormality (NO in ST10), DISK1
The process proceeds to the failure generation routine (ST101), while "1" is set to bit0 of the disk status register 25.
After that, an alarm is displayed.

Since it has been determined that the disk state of DISK1 is normal (YES in ST10), DISK1 is subsequently executed.
1 to determine the data load state. Since bit 1 is "0", it is determined that the load is "normal load" (Y in ST11).
ES).

When bit1 is "1",
It is determined that the data is abnormal (NO in ST11). Then, the control unit (such as the CPU 11) shifts to the data abnormal routine of the disk 1 (ST111).

Since it was determined that the disk state of DISK1 was normal (YES in ST11), the dual control board 1
4 (and the control unit), from the one disk information storage unit 21 shown in FIG. 2 for the normal and non-replaced DISC 1 shown in FIG.
1) is obtained (ST12), and this is temporarily stored in the memory 13.

That is, the other hard disk drive (DI
After the replacement of the SK2) and after the power was turned on, the original one-disk storage capacity (the original total number of sectors n1) is acquired from the one-disk information storage unit 21 of the one-disk drive (DISK1) (ST12). I do.

Subsequently, the duplex control board 14 diagnoses the other hard disk drive (DISK2) after the replacement according to a command from the control unit (CPU 11 or the like). Since bit 0 of the other disk status register 35 shown in FIG. 3 is "0", it is determined that the disk is normal (YES in ST13).

If it is determined that some trouble has occurred and a trouble has occurred (NO in ST13), DISK2
The process proceeds to the failure generation routine (ST131), and "1" is set to bit0 of the disk status register 35.
After that, an alarm is displayed.

Since it has been determined that the disk state of DISK2 is normal (YES in ST13), DISK2 is subsequently executed.
Then, the data loading state of the second data is determined. Since bit1 is still "1", it is determined that "data is abnormal" (ST14).
NO).

When bit1 is "0",
It is determined as "normal load" (YES in ST11). Then, the OS is loaded by the control unit (such as the CPU 11) (ST141).

If it is determined that the disk state of the disk 2 is abnormal (NO in ST14), the duplex control board 14 (and the control unit) re-installs the newly replaced disk.
The other disk information storage unit 31 shown in FIG.
Then, the original other disk storage capacity (total number of sectors = n2) is obtained (ST15), and this is temporarily stored in the memory 13.

Here, capacity determination means (CPU 11 and the like)
Determines whether the original storage capacity n1 of DISK1 is equal to the original storage capacity n2 of DISK2 (n1 = n2) (ST16).

If it is determined that they are equal (n1 = n2) (YES in ST16), the process proceeds to ST19. That is,
The data copy control means (CPU 11 etc.)
Start copying the data in ISK1 to DISK2 (S
T19). The data copy time is determined by the storage capacity n2 (= n1
... for example, a time length determined by 5 GB) (for example, 10 minutes)
It is.

However, if it is determined that they are not equal (S
(NO in T16), it is determined whether or not the storage capacity n2 is smaller than the storage capacity n1 (n1> n2) (ST17).

If it is determined that the storage capacity n2 is smaller (smaller value) than the storage capacity n1 (YES in ST17), that is, the storage capacity n2 (for example, 3G) is the value of the storage capacity n1 (5GB). If it is determined that the value is smaller than (NO in ST16, YES in ST17),
If the data in DISK1 starts to be copied to DISK2 as it is, an overflow occurs.

Accordingly, a notification that data copying is impossible is given. Here, error display control means (CPU 11 and the like)
However, by displaying an error on the display 16 (ST171), the operator can be notified that data copying is not possible.

Now, it is determined that the storage capacity n2 is not smaller (not smaller) than the storage capacity n1 (N in ST17).
O), that is, the storage capacity n2 (for example, 10G
If it is determined that the value of B) is larger than the value of the storage capacity n1 (5 GB) (NO in ST16, NO in ST17), it leads to a longer copy time.

That is, a copy time of 10 minutes at 5 GB is
Twice at 10 GB, it takes 20 minutes. Due to operating hours,
The storage capacity n2 of the DISK2 after the replacement is, for example, 20 GB,
If the copy time increases to 40 GB,.
Minutes, 80 minutes,...

Therefore, the storage capacity rewriting setting control means (CP
U11 etc.) is the storage capacity n2 of DIDK2 (10 GB)
To the storage capacity n1 (5 GB) of DISK1 (ST18). Thereafter, the data copy control means (C
PU11) starts copying from DIDK1 to DISK2 (ST19). When copying is performed for the storage capacity n1 (5 GB), the process ends (YES in ST20). On the other hand, bit1 of the disk status register 35 is switched from "1" to "0".

Then, the data validity determining means (CPU 1
Since the bit 1 of the disk status register 35 is “0”, the duplex control board 14 and the like determine that the disk is normal (YES in ST14). Thus, the control unit (CPU
11 etc.) to load the OS (ST141).
That is, the restart after replacing the DISK 2 can be performed quickly.

In the first embodiment, however, the DI
The original other disk storage capacity n2 stored in the other disk information storage unit 31 of SK2 can be rewritten and stored in the original one disk storage capacity n1 obtained from the one disk information storage unit 21 of DISK1. DIS
Since all the data stored in DISK1 can be copied to DISK2 with the storage capacity of K2 and the storage capacity of normal DISK1 having the same value (n1) having a small value, the copy time does not increase cumulatively.

That is, even if the storage capacity after the replacement is larger than the storage capacity before the replacement, it is possible to prevent the double reconstruction (copy) time from being prolonged, and
Since the storage capacity conversion can be performed automatically, the management burden on the hard disk can be reduced.

When the power is turned on after replacement, both DIs
SK1 and SK2 are accessed to automatically determine which DISK1 is normal (this time non-replacement) DISK1 (ST10 to ST14 in FIG. 4), and the storage capacity n2 of the subsequently replaced DISK2 is normal. It is automatically determined whether or not the storage capacity of the disk DISK1 is equal to or more than n1 (ST16, ST1).
7) is done.

When the storage capacity n2 is automatically determined to be equal to or larger than the storage capacity n1, the other disk storage capacity n2 stored in the other disk information storage unit 31 is acquired from the one disk information storage unit 21. Rewriting and storing in the storage capacity n1 can be automatically performed, and when it is automatically determined that the storage capacity n2 is not equal to or more than the storage capacity n1, an alarm is displayed. It can be performed promptly without interruption, and early restart of the server (10) or the like in which the server is introduced can be secured.
Even if the DISK 2 after the replacement has insufficient storage capacity, a countermeasure can be taken promptly by using the alarm display as a clue.

When it is automatically determined that the storage capacity n2 of the DISK2 after replacement is not equal to or larger than the storage capacity n1 of the normal DISK1 (YES in ST17 of FIG. 4), it is notified that data copying is not possible (ST171). )
Overflow and useless copying operation itself can be avoided.

Further, one hard disk drive (DIS)
K1) Product sales data stored in 20 (for example,
Setting data for merchandise registration and accounting, merchandise files, sales files, etc.
Since the product can be copied to the ISK2) 30, it is possible to continuously and smoothly carry out the merchandise sales business, and it is also possible to exchange the hard disk device even with a cashier or the like who does not necessarily have high computer knowledge, and the handling thereof is simple.

(Second Embodiment) In the second embodiment, the basic configuration and functions are the same as those of the first embodiment (FIG. 1).
4), but the storage capacity n1 of the hard disk device (DISK1) is changed to the current storage capacity m1 in parentheses in FIG. 4 (ST12, ST16, ST17 and ST18) actually used at that time. It is formed so that data duplication can be reconstructed.

That is, after the other hard disk drive (DISK2) 30 in which the trouble (abnormality or the like) has occurred is replaced with a new other hard disk drive (DISK2) 30, the power is turned on, and then the normal and non-replaced one hard disk drive (DISK2) 30 DISK 1) One disk information storage unit 2 of 20
1 can acquire the one disk storage capacity (the number of current sectors m1) shown in FIG. 2, and acquire the other disk storage capacity n2 stored in the other disk information storage section 31 of the new DISK 2 from the one disk information storage section 21. All the data stored in DISK1 is formed so that the storage capacity of DISK2 after replacement and the storage capacity of normal DISK1 are the same (m1), with the current sector number (one disk storage capacity) m1 being the rewritable storage. It is formed on DISK2 so that copying (data duplication reconstruction) is possible.

More specifically, in FIG. 4, the "total number of sectors n1 of DISK1" in ST12 in the first embodiment is changed to "D".
The current total sector number m1 of ISK1 is added to "n" of ST16.
1 = n2 ”to“ m1 = n2 ”, and“ n1> n ”in ST17.
2 is replaced with "m1>n2", and "Set the total number of sectors n2 of DISK2 to n1" in ST18 is replaced with "Set m1 to the total number of sectors n2 of DISK2".

According to the second embodiment,
The storage capacity of DISK1 is copied to the storage capacity n2 of DISK2 after replacement (it can also be implemented as m2) as the current storage capacity m1 actually used at that time instead of the original storage capacity n1. . The current storage capacity m1 (for example, 4 GB) is equal to the original storage capacity n1.
Since the value is smaller than (5 GB), it is possible not only to prevent the duplex reconstruction time (total copy time) from being prolonged, but also to further shorten the time to 8 minutes from 10 minutes at 5 GB.

According to this embodiment, the same operation and effect as those of the first embodiment can be obtained. In addition, all of the data stored in the normal DISK 1 is replaced with the new DISK 2. The data copy time can be further reduced while ensuring that data is copied reliably.

[0077]

According to the first aspect of the present invention, after the other hard disk drive is replaced and after the power is turned on, the other disk storage capacity stored in the other disk information storage unit of the other hard disk drive is changed to the one disk information storage unit. From the storage capacity of the one hard disk drive after the replacement, and the same data storage capacity of the other hard disk drive as the storage capacity of the normal one hard disk drive. Since the hard disk drive is a duplication system formed so as to be able to be copied, even if the storage capacity after the replacement may be larger than the storage capacity before the replacement, the cumulative rebuilding (copying) time is cumulative. Can be prevented from being extended for a long time, and the storage capacity can be automatically converted. It can reduce the administrative burden of the disk.

According to the second aspect of the present invention, both the hard disk drives are accessed after the power is turned on, and it is possible to automatically determine which one of the hard disk drives is normal and the one is the hard disk drive. On the other hand, since the storage capacity of the other hard disk drive is automatically determined to be normal, it can be automatically determined whether or not the storage capacity of the hard disk drive is equal to or larger than the storage capacity of the hard disk drive. In addition to the above, it is possible to automatically determine which one of the normal hard disk drive and the other hard disk drive after replacement and to determine the magnitude of the storage capacity. It can be performed quickly without any trouble, and early restart of a server or the like in which it is installed can be secured. Even if the hard disk device after replacement has insufficient storage capacity, measures can be taken promptly.

According to the third aspect of the present invention, when it is automatically determined that the replaced storage capacity of the other hard disk drive is not larger than the storage capacity of the normal one hard disk drive, it is notified that data cannot be copied. Since it is formed as possible, the same effect as that of the invention of claim 2 can be obtained, and furthermore, overflow and useless copying operation itself can be avoided.

Further, according to the invention of claim 4, on the other hand, the storage capacity of the hard disk drive is the current storage capacity actually used at that time, so that in each of the inventions of claims 1 to 3, In addition to being able to achieve the same effect as above, while ensuring that all the data stored in the normal one hard disk drive is reliably copied to the other hard disk drive after replacement,
Data copy time can be further reduced.

Furthermore, according to the fifth aspect of the present invention, since the data stored in both the hard disk devices is the merchandise sales data, the same effects as those of the first to fourth aspects of the invention can be obtained. On the other hand, the merchandise sales business can be performed continuously and smoothly, and the hard disk device can be replaced even by a cashier or the like who does not necessarily have high computer knowledge, and the handling is easy.

[Brief description of the drawings]

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

FIG. 2 is a diagram for explaining an information storage unit in the hard disk device.

FIG. 3 is a diagram for explaining a disk status register in the hard disk device.

FIG. 4 is a flowchart for explaining the operation and operation.

FIG. 5 is a diagram for explaining a conventional example.

FIG. 6 is a flowchart for explaining the operation and operation of the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 In-store computer 11 CPU 12 BIOS 13 Memory 14 Duplex control board 20 One hard disk device (DISK1) 21 One disk information storage unit 25 One disk status register 30 The other hard disk device (DISK2) 31 Other disk information storage unit 35 Other disk Status register

Claims (5)

[Claims] Claims: 1. In a hard disk drive duplex system constructed so that both read / write accesses a hard disk drive, one of the hard disk drives which is normal after the other hard disk drive is replaced and after the power is turned on. One disk storage capacity can be obtained from the disk information storage unit, and the other disk storage capacity stored in the other disk information storage unit of the other hard disk drive can be rewritten and stored in the one disk storage capacity obtained from the one disk information storage unit. A hard disk drive that is formed so that the storage capacity of the other hard disk drive after replacement is the same as the storage capacity of the normal one hard disk drive and all data stored in one hard disk drive can be copied to the other hard disk drive. Doubled Temu. 2. The two hard disk drives are accessed after the power is turned on, and it is possible to automatically determine which one of the hard disk drives is normal and which one of the hard disk drives is normal, and to exchange the other hard disk drive. 2. The duplex system for a hard disk drive according to claim 1, wherein the system is formed so as to be able to automatically determine whether or not the storage capacity is equal to or larger than the storage capacity of the one hard disk drive automatically determined to be normal. 3. A storage capacity of the exchanged second hard disk device is automatically determined to be normal. If it is automatically determined that the storage capacity of the one hard disk device is not more than the storage capacity, it is possible to notify that data cannot be copied. 3. The duplex system for a hard disk drive according to claim 2, wherein: 4. The hard disk drive according to claim 1, wherein the storage capacity of said one hard disk drive is a current storage capacity actually used at that time. Duplex system. 5. The data stored in the both hard disk devices is merchandise sales data.
The duplex system for a hard disk device according to any one of the above.