JP2002229742A - Access switching control device and access switching control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an access switching control device gaining access to another HDD(hard disk device) even when one HDD fails, quickly recovering a system, and invariably maintaining the system at a normal operation state. SOLUTION: The system is provided with a plurality of HDDs 6A-6C storing the information of the same content, an access switching means selectively switching a plurality of HDDs 6A-6C, a means detecting a freeze of a system main body section, and a means, which applies a system reset when detecting the freeze, switches the HDD presently connected to the system main body section with another HDD, then reactivates the system main body section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an HDD (H
The present invention relates to an access switching control device and an access switching control method capable of eliminating a failure related to HDD access in a computer system, various control devices, and the like equipped with an “ard disk drive”.

[0002]

2. Description of the Related Art In recent years, not only computer systems such as personal computers, but also various control devices (controllers) and the like, the OS (Operating System), programs, data, and the like have tended to increase in size.
(Hard Disk Drive) has been increasingly used.

[0003] HDDs have also been installed in devices that require continuous operation, such as server computers, various service terminals, vending machines, and monitoring devices.

FIG. 5 shows an example of a configuration of an access means for an HDD provided in a conventional personal computer or controller.

[0005] This conventional system comprises a CPU unit 1
And HDC (Hard Disk Control)
r) 5, a master (MASTER) HDD 6 whose access is controlled by the HDC 5, a slave (SLAVE) HDD 7 similarly controlled by the HDC 5, and the like.

The CPU unit 1 stores a CPU 2 for executing a system program, a RAM 3 for loading a program and temporarily storing data, a system program, fixed programs and data, and the like. It is composed of a ROM 4 and the like.

[0007] Master HDD 6 and slave HDD
7 is connected by a single cable in a daisy chain system, and setting of jumpers and switches of each HDD 6 and 7 (jumper type) or cable selection of each HDD (C
Able Select) input signal level (CABL)
E SELECT expression) specifies whether the device is a master or a slave. The slave HDD 7 is added when the capacity of the master HDD 6 is insufficient, and can be omitted.

[0008]

SUMMARY OF THE INVENTION However, HDD
For example, in a computer system or various control devices equipped with the HDD, a failure related to the HDD may occur when performing continuous operation.

The HDD includes a moving part such as a spindle motor or the like as a constituent element, and is susceptible to shock and vibration due to a precision mechanism, and has lower durability and reliability than semiconductors (CPU and memory).

As a result, there arise problems such as a read / write error and a failure to disable data access.

In addition, even if the HDD itself is normal, unauthorized access occurs due to unexpected combination or operation of applications, unstable operation due to lack of system resources, etc., and the contents of the HDD are often illegally rewritten.

Furthermore, recently, computer viruses often intentionally change or delete the contents of the HDD. Thus, if the contents of the HDD are intentionally changed or deleted by a computer virus or the like, RAID (Redundant Arrays) is used.
f Inexpensive Discs) HD
Even D cannot recover.

As described above, when the contents of the HDD cannot be accessed normally, the system freezes, making continuous operation impossible, making it impossible to continue control and service, often causing serious damage.

In particular, the OS and important application programs are stored in the master HDD, and if it cannot be accessed normally, the damage to the system will be large.

Accordingly, an object of the present invention is to provide an access switch that can access another HDD and quickly restore the system even if one HDD fails, so that the system can always be kept in a normal operation state. A control device and an access switching control method are provided.

[0016]

SUMMARY OF THE INVENTION The present invention is an apparatus for controlling access switching to a storage medium for providing necessary information to a system main body, wherein a plurality of pieces of information having the same contents are stored. A storage medium, access switching means for switching selection of the plurality of storage media, freeze detection means for detecting whether or not the system main body has been frozen, and when the freeze is detected, performing a system reset, After the currently selected storage medium is switched to another storage medium, the access switching control device is configured by including restart control means for executing a restart of the system main body.

According to the present invention, there is provided a method for controlling access switching to a storage medium for providing necessary information to a system main unit, wherein a plurality of storage media storing information of the same content are used. A freeze detection step of detecting whether or not the system body has frozen, and after detecting the freeze, after resetting the system and switching the storage medium currently connected to the system body to another storage medium, And a restart control step of performing a restart of the system body, thereby providing an access switching control method.

The present invention is a medium recording a program for controlling access switching to a storage medium for providing necessary information to a system main unit by a computer, and the control program is stored in the same computer. Using a plurality of storage media in which information of the content is stored, it is detected whether or not the system main body is frozen. When the freeze is detected, a system reset is performed, and the system main body is currently connected to the system main body. After switching the storage medium to another storage medium, the system main body is restarted to provide a medium in which an access switching control program is recorded.

The present invention is a program for controlling access switching to a storage medium that provides information necessary for a system main body. The program is recorded on a readable recording medium. Using a plurality of storage media storing the same information, detecting whether or not the system main body is frozen; and, upon detecting the freeze, resetting the system and currently connecting to the system main body. Performing a restart of the system main body after switching the storage medium to another storage medium, thereby providing an access switching control program.

Here, when the connection is switched, two storage media are connected in a master / slave connection system, and a master / slave storage medium is operated by operating a master / slave selection signal. May be switched.

In switching the connection, a plurality of controllers are further used, the storage medium is connected to each controller, and the storage medium is replaced by operating a controller selection signal to replace the storage medium. You may switch.

After the storage medium is switched during the freeze, and after the system is normally restarted, as the background processing of the system main body, the entire storage medium that has been operated before the switching is executed. May be copied.

After the information has been normally rebooted, the entire contents of the operating storage medium are copied to the operating storage medium before the switching, and then periodically or Each time writing or rewriting is performed on the operating storage medium, the contents of the operating storage medium may be mirrored / backed up to another storage medium.

Verify copying is performed when copying all the contents of the operating storage medium to the storage medium that was operating before switching, and when an error is detected, initialization processing is performed on the copy destination storage medium. After the automatic execution, the storage medium may be copied again.

Display means for distinguishing each storage medium is further used, and a verify copy is performed when copying the entire contents of the storage medium to the storage medium that was operating before switching during operation,
When an error is detected, initialization processing is automatically performed on the copy destination storage medium, and then verify copy for copying the storage medium is performed again. When an error is detected again, The display means corresponding to the copy destination storage medium may be displayed.

[0026]

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

[First Example] A first embodiment of the present invention will be described with reference to FIGS. The description of the same parts as those of the above-described conventional example (see FIG. 5) is omitted and the same reference numerals are given.

(Outline) First, the outline of the present invention will be described.

According to the present invention, a hard disk (HDD) as a storage medium for providing necessary information to a system main body is provided.
Drive), when controlling access, a plurality of HDDs in which the same contents of OS, programs, and data are written, an access switching unit capable of selectively switching access to a plurality of HDDs, and a system freeze And a means for resetting the system by resetting the system when the freeze detecting means detects a freeze, and accessing the currently selected HDD during execution of the system reset at the time of the system freeze. And reboot execution means for executing a reboot after switching to another HDD by the switching means.

With such access control, even if the system freezes due to a problem with the HDD, the system can be quickly restored.

Hereinafter, a specific example will be described.

(System Configuration) FIG. 2 shows a maintenance-free HD as an access switching control device according to the present invention.
1 shows a system configuration example of a D control device.

This system comprises a CPU unit 1 and an HD
C (Hard Disk Controller) 5
And three master HDDs 6A, 6B, 6C in which the same information contents (OS, programs, data, etc.) are written.
, An access switching unit 8 and a freeze detection unit 9.

The CPU unit 1 includes a CPU 2 for executing various programs of the system, and an R for use as an area for loading various programs and temporarily storing data.
An AM 3 and a ROM 4 storing a control program (see FIG. 1), a system program, other fixed programs, data, and the like according to the present invention.

The HDC 5 controls access to the master HDDs 6A, 6B, 6C in response to a request from the CPU unit 1.

The access switching unit 8 controls the BUS (usually the HDC 5 and the master HD) of the control signal group sent from the HDC 5.
D6A, 6B, 6C are connected by a flat cable,
A control signal group and a power supply line pass therethrough. Hereinafter, H
DC BUS) is initially connected via the path A (that is, connected to the HDD 6A), but every time a control signal is input to the select input terminal S, the path is switched from the currently connected A to the B The order is switched in the order of → C → A → B → C..., Whereby one of the HDDs is selected and can be accessed.

The freeze detecting section 9 detects whether or not the present system has been frozen, and when detecting that the system has been frozen, resets the CPU unit 1 and simultaneously sends a control signal to the access switching section 8. The HDC 5 controls the path of the master HDDs 6A, 6B, and 6C, which are transmitted and controlled by the select input terminal S.

The freeze detecting section 9 normally uses a watchdog timer, and uses the output signal indicating the abnormality detection of the watchdog timer as a system reset signal 100 as a select input terminal S of the CPU unit 1 and the access switching section 8. To supply.

(Access Switching Control) Next, access switching control of the present system will be described.

FIG. 1 is a flowchart showing an example of access switching control processing.

It is assumed that the access switching section 8 is first connected to the HDD 6A via the path A. Note that this connection state is determined by the slave H shown in the conventional example (see FIG. 5).
This is the same as when DD7 is omitted.

In step S1, the system is executing the application program in the connection state of the path A.

In step S2, a process of detecting a freeze (ie, occurrence of a failure) is performed by a watchdog timer or the like in parallel with the execution of the application in step S1. If no freeze occurs, step S1
And the execution of the application program is continued. When a freeze occurs, the freeze detection circuit outputs a system reset signal, and the process proceeds to S4. In step S3, the access switching unit 8 switches the currently connected path from A to B when the system reset signal 100 is input to the select input terminal S. By this switching, the HDC 5 passes through the path B,
It will be connected to the master HDD 6B.

At the same time as the path switching, reboot is performed again. In the master HDD 6B, the master HDD 6A
Since the same contents as in the normal operation were written, the system normally reboots and returns to S1. This allows
Even after the failure, the system can be operated normally.

The processing loop of the above steps S1, S2, S3 is as follows:
Termination of the application or power of the system
It continues to run until it turns off. During this time, even if a failure occurs in the HDD, it can be recovered and the application can be executed normally. Thereafter, the process is terminated when the application is terminated or the power of the system is turned off. (S4) In this normal state, the master HDD
Even if some trouble occurs in the 6B, the HDD 6C
And the system can continue to operate normally as well.

As described above, the system is configured by the HDD 6
Even if the system freezes due to a problem related to A and 6B, the system can be quickly restored, and the system can continue normal operation. Therefore, it is possible to stably and continuously operate devices equipped with HDDs that require continuous operation, such as server computers, various service terminals, vending machines, and monitoring devices.

[Second Example] A second embodiment of the present invention will be described with reference to FIG. The description of the same parts as those in the first example is omitted, and the same reference numerals are given.

In the first example described above, a method of directly switching the HDD BUS is adopted as the HDD access switching means, but the HDD BUS is an IDE type HDD.
44 (including power supply lines), more in SCSI type. For this reason, electronically switching the HDDBUS may be quite large and expensive.

Therefore, in this embodiment, in the maintenance-free HDD control device described above, two HDDs are connected in a master / slave connection system as access switching means, and a master / slave selection signal is operated. This is an example of a case where control is performed to switch between a master HDD and a slave HDD.

Hereinafter, a specific example will be described.

FIG. 3 shows a system configuration example of the maintenance-free HDD control device.

Reference numerals 6A and 6B denote master HDDs having the same configuration as that of the first example (see FIG. 2). The contents of the same information are written in advance in the master HDDs 6A and 6B, and the master HDDs are daisy-chained.
TER / SLAVE connection.

However, the MAST output from the HDC 5
A jumper switch for selecting ER / SLAVE or a cable select (Cable Select) input line is controlled by a special control signal as described later.

Reference numeral 10 denotes a selector which constitutes an access switching means. The selector 10 changes the cable select signal 110 sent from the HDC 5 based on the control of the system reset signal 100 inputted to the select input terminal S, to the output terminals A,
It has the function of sorting to either B.

(Access Switching Control) In such a system configuration, the selector 10 first outputs the cable select signal 110 input from the HDC 5 to the input terminal Y to the output terminal A.

In this output state, the HDC 5 can access the master HDD 6A.

When some trouble occurs in the master HDD 6A, the system freezes and the freeze detecting section 9 outputs a system reset signal 100.

When the system reset signal 100 is input to the select input terminal S of the selector 10, the cable select signal 110 is output to the output terminal B.

In this way, the access is switched, and the master HDD 6B can be accessed. At the same time, the system is reset and the system is rebooted.

The master HDD 6B has a master HDD
Since the same contents as when 6A was operating normally are written, the system is normally rebooted and the system can operate normally thereafter.

In the present embodiment, the selector 10 having a function of distributing the cable select signal 110 to one of the output terminals A and B based on the system reset signal 100 input to the select input terminal S is used. Although configured, other configurations may be used.

For example, two terminals of the jumper switch for master setting are respectively pulled out from each of the HDDs 6A and 6B, only one of the two terminals is short-circuited, and the two terminals which are short-circuited based on the cable select signal 110 are sequentially switched. With the configuration, the same operation and effect can be obtained. In this case, the commonly used HD
There is an advantage that the flat cable for CBUS can be diverted as it is.

As described above, the two HDDs are connected in MASTER / SLAVE in a daisy chain system, and the HDDs can be easily operated by operating the jumper switches for selecting MASTER / SLAVE or the cable select input lines. Can be selectively switched, whereby a simpler and less expensive configuration can be realized as compared with the first example described above.

Further, in this example, as shown in FIG. 3, the processing for switching between two HDDs has been described.
The number of units can be increased as long as the drive capability of the HDC allows. However, it is necessary that only one of the selectors can be set as the master.

[Third Example] A third embodiment of the present invention will be described with reference to FIG. The description of the same parts as those in the above-described examples is omitted, and the same reference numerals are given.

In each of the above-described examples, only one HDD can be accessed simultaneously. However, multiple HDDs are
A plurality of HDDs may be used as one set, such as when using a D configuration.

Therefore, in this example, in the maintenance-free HDD control device described above, a plurality of HDCs (Hard Disk Controllers) are used as access switching means.
This is an example in which HDDs are connected to each HDC equipped with an HDD and the HDDs are switched by operating the HDC selection signal to switch the HDDs.

FIG. 4 shows an example of the system configuration of a maintenance-free HDD control device.

The CPU unit 1 has two HDCs 5
A and 5B are connected. HDCs 5A and 5B are connected to master HDDs 6A and 6B, respectively.

The master HDDs 6A and 6B are connected to the slave H
DD7A, 7B and daisy-chain system respectively
ASTER / SLAVE connection. Slave HD
The contents of the same information as those of the master HDDs 6A and 6B are written in advance in D7A and 7B.

The selector 10 converts the chip select signal 120 input to the input terminal Y from the CPU unit 1 into the system reset signal 1 input to the select input terminal S.
The HDC 5A or 5B can be activated by sorting to either the HDC 5A or 5B based on the control of 00.

(Access Switching Control) In such a system configuration, the selector 11 first outputs the chip select signal 120 input to the input terminal Y to the output terminal A.

In this output state, the MAS is connected to the HDC 5A.
The master HDD 6A and the slave HDD 7A connected by TER / SLAVE can be accessed.

In this connection state, if any failure occurs in the master HDD 6A and the slave HDD 7A, the system freezes, and the freeze detector 9 outputs a system reset signal 100 to the selector 10.

When the system reset signal 100 is input to the select input terminal S of the selector 10, switching is performed so that the chip select signal 120 is output to the output terminal B side.

With such access switching control, the master HDD 6B and the slave 7B can be accessed, and at the same time, the system is reset and the system is rebooted.

Since the same contents as when the master HDD 6B and the slave 7B were operating normally are written in the newly switched master HDD 6B and slave 7B, the system is normally rebooted, and the system is normally restored thereafter. Can work.

As described above, the HDCs 5A, 5B and the HDDs 6A, 6B, 7A, 7B connected to them.
, And the chip select signal 120 input to the HDCs 5A and 5B can be sequentially switched by the system reset signal 100 input to the selector 10 so that the HDD is configured in a RAID configuration or the like. The present system can be applied to a case in which is used as one set.

[Fourth Example] A fourth embodiment of the present invention will be described. The description of the same parts as those in the above-described examples is omitted, and the same reference numerals are given.

In this example, in the maintenance-free HDD control device shown in FIGS. 2 to 4, the HDD is switched at the time of system freeze, and after the OS and the program are normally rebooted, the background processing of the system is performed. This is an example of a case in which control is performed to copy all the contents of the operating HDD to the HDD that was operating before switching.

That is, in the maintenance-free HDD control device described above, the access switching means (the access switching unit 8 in FIG. 2 and the selector 10 in FIGS. 3 and 4) of those HDDs is temporarily set to the immediately preceding switching state. Provide a return function.

For example, by providing a reverse input terminal R in the access switching means and the selector and operating the reverse input terminal R by the I / O port of the CPU unit 1,
Temporarily return to the state before the currently selected state (hereinafter referred to as the previous state). And the reverse input terminal R
By stopping the operation, the user can return to the current state (hereinafter, referred to as the current state).

(Access Switching Control) In such a system configuration, by performing the access switching control of each of the above-described Examples 1 to 3, the H selected in the previous state is obtained.
If any trouble occurs in the DD and normal access is no longer possible, the system freezes and the freeze detecting unit 9
, The system is switched to the HDD selected in the current state, and the system is normally rebooted.

In this current state, a part of the contents of the HDD is temporarily loaded into the RAM, and the state is temporarily switched to the previous state, and the contents of the RAM are written to the corresponding part of the HDD selected in the state before the state. Is repeated, all the contents of the currently selected HDD are copied to the HDD selected in the previous state.

As described above, when the system is frozen, the HDD is switched, and after the OS and the program are normally rebooted, as the background processing of the system, all the contents of the operating HDD are switched to the HD operating before the switching.
D, even if there are only two (two sets) or three (three sets) HDDs to be switched, as in Examples 1 to 3, even if the system freezes many times,
By switching D, it is possible to reboot normally and recover.

[Fifth Example] A fifth embodiment of the present invention will be described. The description of the same parts as those in the above-described examples is omitted, and the same reference numerals are given.

In this example, in the maintenance-free HDD control device shown in FIGS. 2 to 4 described above, after the OS and the program are normally rebooted, the entire contents of the operating HDD are executed as background processing of the system. After copying to the HDD that was operating before the switch, the contents of the operating HDD are mirrored and backed up to other HDDs (check the file structure) periodically or whenever writing or rewriting is performed on the operating HDD. This is an example in which control is performed such that only different portions are rewritten to be the same.

The CPU 2 can detect regular time intervals and writing and rewriting to the HDD.

As described above, as the background processing of the system, all the contents of the operating HDD are copied to the operating HDD before the switching, and then the writing processing and the rewriting processing are performed periodically or in the operating HDD. Each time the operation is performed, the contents of the operating HDD are mirrored and backed up to the HDD selected in the previous state, so that HDDs such as controllers for various service terminals, vending machines, monitoring devices, etc. Not only systems without writing and rewriting, but also HDs such as server computers
It can be applied to a system in which writing and rewriting to D are performed.

[Sixth Example] A sixth embodiment of the present invention will be described. The description of the same parts as those in the above-described examples is omitted, and the same reference numerals are given.

In this example, in the maintenance-free HDD control device shown in FIGS. 2 to 4 described above, verify copying is performed when copying all the contents of the operating HDD to the HDD that was operating before the switching. When an error is detected, initialization processing (FDI
SK command, FORMAT command, assignment of alternative sectors to bad sectors, etc.)
This is an example of a case where control is performed to copy the HDD again.

As described above, verify copying is performed, and when an error is detected, initialization processing such as FDISK command, FORMAT command, assignment of a substitute sector to a defective sector, and the like are automatically performed on the copy destination HDD. After that, if the HDD is destroyed in units of tracks or sectors, recovery is performed as long as the remaining capacity is larger than the total capacity of the OS, programs, data, etc. written to the HDD. Is possible.

[Seventh Example] A seventh embodiment of the present invention will be described. The description of the same parts as those in the above-described examples is omitted, and the same reference numerals are given.

In this example, in the maintenance-free HDD control device shown in FIGS.
Display means capable of distinguishing between the two is provided. During the operation, verify copying is performed when copying the entire contents of the HDD to the HDD that was operating before switching, and when an error is detected,
After the initialization processing (the FDISK command, the FORMAT command, the assignment of the substitute sector to the defective sector, etc.) is automatically performed on the copy destination HDD,
This is an example of a case where a verify copy for copying an HDD is performed, and if an error is detected again, control is performed to display a display means corresponding to the copy destination HDD.

As described above, after the initialization process is automatically performed, the verify copy for copying the HDD is performed again, and when an error is detected again, the display indicating the copy destination HDD is performed. By displaying the means, the maintenance person of the system can know only by looking at the display means that the HDD indicated by the display means has a physical failure, and simply replace the HDD with another new HDD. Thus, continuous operation of the system can be maintained.

The present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, and a printer).
The present invention may be applied to an apparatus including one device (for example, a small image processing device such as a PDA (personal information management) device, a copying machine, and a facsimile device).

The present invention can of course be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus. Then, a storage medium storing a program represented by software for achieving the present invention is supplied to a system or an apparatus, and the computer (or CPU or M) of the system or the apparatus is supplied.
(PU) reads out and executes the program code stored in the storage medium, so that the effects of the present invention can be enjoyed.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

Examples of a storage medium for supplying the program code include a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, and CD.
-R, magnetic tape, nonvolatile memory card (IC memory card), ROM (mask ROM, flash EEP)
ROM etc.) can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instructions of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0102]

As described above, according to the present invention,
A plurality of storage media (for example, H
DD), an access switching unit for switching selection of a plurality of HDDs, a unit for detecting that the system main body is frozen, and a system reset when a freeze is detected, the system being reset and being currently connected to the system main body. A means is provided for restarting the system main unit after switching the existing HDD to another HDD. Therefore, even if the system freezes due to a problem related to the HDD, the system can be quickly restored and the normal operation state maintained. This makes it possible to continuously operate devices equipped with HDDs that require continuous operation, such as server computers, various service terminals, vending machines, and monitoring devices, in a stable state, and Even if the contents of the HDD are maliciously altered or deleted by a computer virus, etc. , And restore the speed, it is possible to continue the continuous operation.

Further, according to the present invention, as an access switching means, two HDDs are connected in a master / slave connection system, and a master / slave HDD is switched by operating a master / slave selection signal. Therefore, the selection of the HDD can be switched more easily, and the configuration can be reduced.

Further, according to the present invention, a plurality of HDCs are provided as access switching means, HDDs are connected to each HDC, and the HDDs are exchanged by operating the HDC selection signals to exchange the HDDs. Since the switching is controlled, the system according to the present invention can be applied to a case where HDDs are configured in a RAID configuration or a case where a plurality of HDDs are used as one set.

According to the present invention, when the system is frozen, the HDD is switched, and after the OS and the program are normally rebooted, the background processing of the system is executed.
H that was operating before switching all the contents of the operating HDD
Copying to DD, HD to be switched
Even if there are only two (two sets) or three (three sets) D, even if the system freezes many times, the HDD can be switched and rebooted normally to recover.

Further, according to the present invention, after the OS and the program are normally rebooted, as the background processing of the system, after copying all the contents of the operating HDD to the HDD which was operating before the switching, H periodically or during operation
Each time the DD is written or rewritten, the active H
Since the contents of the DD are mirrored / backed up to another HDD (check the file structure and rewrite only the different parts so that they are the same), controllers for various service terminals, vending machines, monitoring devices, etc. The present invention can be applied not only to a system in which writing and rewriting of the HDD is not performed, but also to a system in which writing and rewriting of the HDD are performed, such as a server computer.

Further, according to the present invention, verify copying is performed when copying all the contents of the operating HDD to the HDD that was operating before the switching, and when an error is detected, the verify copying is performed to the copy destination HDD. The HDD is copied again after automatically performing initialization processing (FDISK command, FORMAT command, assignment of alternative sectors to bad sectors, etc.), so that even if the HDD is destroyed in track or sector units, OS whose remaining capacity writes to HDD,
Recovery can be performed while the program, data, etc. are larger than the total capacity.

Further, according to the present invention, a display means for distinguishing each HDD is provided, and when copying the entire contents of the HDD to the HDD which was operating before the switching, a verify copy is performed. Is detected, the initialization processing (FDISK command, F
(ORMAT command, assignment of a substitute sector to a defective sector, etc.) is automatically performed, and then verify copying for copying the HDD is performed again. If an error is detected again, the corresponding HDD is copied. Since the display means is displayed, the maintenance person of the system can know only by looking at the display means that the HDD indicated by the display means has a physical failure, and
By simply replacing the HDD with another new HDD, the continuous operation of the system can be maintained.
It is not necessary to write S, programs, data, etc., or even to initialize the format etc. in advance. It is only necessary to replace the HDD with the one just purchased, making maintenance easy and inexpensive. Can be done.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a process of access switching control according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a system configuration example of a maintenance-free HDD control device according to the present invention.

FIG. 3 is a block diagram illustrating a system configuration example of a maintenance-free HDD control device according to a second embodiment of the present invention.

FIG. 4 is a block diagram illustrating a system configuration example of a maintenance-free HDD control device according to a third embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration example of a conventional HDD access switching unit.

[Explanation of symbols]

 Reference Signs List 1 CPU unit 2 CPU 3 RAM 4 ROM 5 HDC 6, 6A, 6B, 6C Master HDD 7, 7A, 7B Slave HDD 8 Access switching unit 9 Freeze detection unit 10 Selector

Claims (28)

[Claims] 1. An apparatus for performing switching control of access to a storage medium that provides information necessary for a system main unit, comprising: a plurality of storage media storing information of the same content; Access switching means for switching selection of a medium, freeze detection means for detecting whether or not the system main body is frozen, and when the freeze is detected, a system reset is performed, and the currently selected storage medium is read. An access switching control device, comprising: restart control means for restarting the system main body after switching to another storage medium. 2. The access switching means connects two storage media in a master / slave connection system and operates a master / slave selection signal to switch between a master storage medium and a slave storage medium. The access switching control device according to claim 1, wherein the switching is performed. 3. The access switching means further comprises a plurality of controllers, wherein the storage medium is connected to each of the controllers, and a controller selection signal is operated to exchange each of the storage media, thereby obtaining the storage. 2. The access switching control device according to claim 1, wherein the medium is switched. 4. A storage medium is switched during said freeze,
2. The system according to claim 1, wherein, after the system is normally restarted, all contents of the operating storage medium are copied to the operating storage medium before switching as background processing of the system main unit. 4. The access switching control device according to any one of claims 3 to 3. 5. After the system is normally rebooted, the background processing of the system main unit is performed as follows:
After copying the entire contents of the operating storage medium to the operating storage medium before switching, periodically, or each time writing or rewriting is performed on the operating storage medium, the contents of the operating storage medium are copied. 5. The access switching control device according to claim 4, wherein the contents are mirrored / backed up to another storage medium. 6. A verify copy is performed when copying all contents of an operating storage medium to a storage medium that was operating before switching, and when an error is detected, initialization is performed on the copy destination storage medium. 5. The access switching control device according to claim 4, wherein after performing the processing automatically, the storage medium is copied again. 7. A display device for distinguishing each storage medium, wherein a verify copy is performed when copying the entire contents of the storage medium to the storage medium that was operating before switching during operation, and an error was detected. In this case, after the initialization processing is automatically performed on the copy destination storage medium, the verify copy for copying the storage medium is performed again, and if an error is detected again, the copy destination storage medium is 7. The access switching control device according to claim 6, wherein the display means corresponding to the information is displayed. 8. A method for controlling access switching for a storage medium that provides information necessary for a system main unit, wherein the system main unit uses a plurality of storage media storing information of the same content. A freeze detection step of detecting whether or not the unit has frozen, and when the freeze is detected, a system reset is performed, and after switching the storage medium currently connected to the system body to another storage medium, An access switching control method, comprising: a restart control step of restarting the system body. 9. When the connection is switched, two storage media are connected in a master / slave connection mode, and a master / slave storage medium is operated by operating a master / slave selection signal. 9. The access switching control method according to claim 8, wherein the switching is performed. 10. When switching the connection, a plurality of controllers are further used, the storage medium is connected to each controller, and a controller selection signal is operated to exchange each of the storage media, thereby enabling the storage to be performed. 9. The access switching control method according to claim 8, wherein the medium is switched. 11. A storage medium is switched at the time of the freeze, and after the system is normally restarted, all contents of the operating storage medium are operated as background processing of the system main body before the switching. The access switching control method according to any one of claims 8 to 10, wherein copying is performed on a storage medium. 12. After the system is normally rebooted, as background processing of the system main body,
After copying the entire contents of the operating storage medium to the operating storage medium before switching, periodically, or each time writing or rewriting is performed on the operating storage medium, the contents of the operating storage medium are copied. 12. The access switching control method according to claim 11, wherein the contents are mirrored / backed up to another storage medium. 13. A verify copy is performed when copying the entire contents of an operating storage medium to a storage medium that was operating before switching, and when an error is detected, initialization is performed on the copy destination storage medium. 12. The method according to claim 11, wherein after the processing is automatically performed, the storage medium is copied again.
The access switching control method described in the above. 14. A display unit capable of distinguishing each storage medium is further used, and a verify copy is performed when copying the entire contents of the storage medium to the storage medium that was operating before switching during operation, and an error was detected. In such a case, after the initialization processing is automatically performed on the copy destination storage medium, verify copy for copying the storage medium is performed again, and if an error is detected again, the copy destination storage medium is 14. The access switching control method according to claim 13, wherein said display means corresponding to the above is displayed. 15. A medium in which a program for controlling access switching to a storage medium for providing necessary information to a system main body by a computer is recorded, wherein the control program has the same contents as the computer. Using a plurality of storage media in which information is stored, detecting whether or not the system main body has been frozen, and performing a system reset when detecting the freeze, the storage medium currently connected to the system main body. A medium in which an access switching control program is recorded, wherein the system switching unit is restarted after switching to another storage medium. 16. When the connection is switched, two storage media are connected in a master / slave connection method, and a master / slave storage medium is operated by operating a master / slave selection signal. 16. A medium recording an access switching control program according to claim 15, wherein the switching is performed. 17. When switching the connection, a plurality of controllers are further used, the storage medium is connected to each of the controllers, and a controller selection signal is operated to exchange the storage media to thereby switch the storage medium. 16. A medium recording an access switching control program according to claim 15, wherein the medium is switched. 18. The storage medium is switched at the time of the freeze, and after the system is normally restarted, the entire contents of the operating storage medium are operated as background processing of the system main body before the switching. 18. A medium recording the access switching control program according to claim 15, wherein the medium is copied to a storage medium. 19. After the information has been successfully rebooted,
As background processing of the system main body, all contents of the operating storage medium are copied to the operating storage medium before switching, and then periodically or written or rewritten to the operating storage medium. 19. The medium according to claim 18, wherein the content of the operating storage medium is mirrored / backed up to another storage medium every time. 20. Verify copy is performed when copying the entire contents of an operating storage medium to a storage medium that was operating before switching, and when an error is detected, initialization is performed on the copy destination storage medium. 19. The method according to claim 18, wherein after the processing is automatically performed, the storage medium is copied again.
A medium on which the access switching control program according to the above is recorded. 21. A display unit capable of distinguishing each storage medium is further used, and a verify copy is performed when copying the entire contents of the storage medium to the storage medium that was operating before switching during operation, and an error was detected. In such a case, after the initialization processing is automatically performed on the copy destination storage medium, verify copy for copying the storage medium is performed again, and if an error is detected again, the copy destination storage medium is 21. The medium storing the access switching control program according to claim 20, wherein the display means corresponding to the program is displayed. 22. A program for performing switching control of access to a storage medium that provides information necessary for a system main unit, wherein the program is recorded on a readable recording medium, and has the same contents. Using a plurality of storage media in which the information is stored, detecting whether or not the system main body has been frozen, and when detecting the freeze, performing a system reset and being currently connected to the system main body. Executing a restart of the system main body after switching from one storage medium to another storage medium. 23. When the connection is switched, two storage media are connected in a master / slave connection system, and a master / slave storage medium is operated by operating a master / slave selection signal. 23. The access switching control program according to claim 22, wherein the switching is performed. 24. When switching the connection, a plurality of controllers are further used, the storage medium is connected to each of the controllers, and a controller selection signal is operated to exchange the storage media to thereby switch the storage medium. The access switching control program according to claim 22, wherein the medium is switched. 25. When the storage medium is switched at the time of the freeze, and after the system is normally restarted, the entire contents of the operating storage medium are operated as background processing of the system main body before the switching. The access switching control program according to any one of claims 22 to 24, wherein the program is copied to a storage medium. 26. After the system is normally rebooted, as background processing of the system main body,
After copying the entire contents of the operating storage medium to the operating storage medium before switching, periodically, or each time writing or rewriting is performed on the operating storage medium, the contents of the operating storage medium are copied. 26. The access switching control program according to claim 25, wherein the contents are mirrored / backed up to another storage medium. 27. Verify copying is performed when copying all the contents of an operating storage medium to a storage medium that was operating before switching, and when an error is detected, initialization is performed on the copy destination storage medium. 26. The method according to claim 25, wherein after the processing is automatically performed, the storage medium is copied again.
An access switching control program according to the above. 28. A display device for distinguishing each storage medium, further comprising: verify copying when copying all contents of the storage medium to the storage medium that was operating before switching during operation, and detecting an error. In such a case, after the initialization processing is automatically performed on the copy destination storage medium, verify copy for copying the storage medium is performed again, and if an error is detected again, the copy destination storage medium is 28. The access switching control program according to claim 27, wherein said display means corresponding to the information is displayed.