JPH11232041A - Data multiplex write device/method and recording medium recording data multiplex write program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten required time until a data multiplex write processing terminates by preferentially selecting a high speed external storage device for selecting the optimum external storage device from the characteristics of the respective external storage devices. SOLUTION: When the request of data multiplex writing is given in a computer system α, a multiplex write instruction is sent to a control part 2 from a multiplex write instruction part 1. A memory 3 collects the normal/abnormal state information on semiconductor files 5a and 5b and magnetic disks 61 and 6b at any time and stores management data on state information and ability information being the ability of the write speed of data against the external storage devices 5a-6b, which are previously stored in the memory 3, on the memory 3. One of the external storage devices 51-6b, which becomes a multiplex write object in an external storage device group 4, is selected in a judgement processing and writing is executed. The selection and writing are repeated and a multiplex write processing terminates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data multiplex writing apparatus for writing data in an external storage device in a computer system in a multiplex manner in order to increase the reliability of the data, and an embodiment thereof. The present invention relates to a method and a recording medium on which a data multiplex writing program is recorded.

[0002]

2. Description of the Related Art Conventionally, in writing data to an external storage device in a computer system, in order to prevent loss of data due to corruption of data stored in one external storage device, without particularly being aware of the type of the external storage device, The same data has been written and stored in two or more external storage devices in a multiplex manner to increase the reliability of the data.

[0003]

However, various types of external storage devices, such as semiconductor files, magnetic disks, and magnetic tapes, exist, and their performance and price, such as data writing speed and storage capacity, are low. There is also variation.

For this reason, conventional multiple writing to external storage devices of different types is performed multiplexing while completely ignoring the characteristics of each external storage device. When data is simultaneously written to an external storage device including a magnetic disk, multiplex writing does not end until writing to a low-speed magnetic disk ends, and there is a problem that the required time increases. .

Therefore, in the prior art, in order to reduce the required time, the writing speed must be unified to a high-speed semiconductor file, and an expensive semiconductor file is newly installed instead of an inexpensive magnetic disk. In this case, there is a problem that the investment cost for the apparatus is increased.

[0006] In addition, when some external storage devices have failed, the above-mentioned problem has occurred similarly.

The main objects to be solved by the present invention are as follows.

A first object of the present invention is to provide a multiplex writing apparatus and method for multiplex writing for selecting and writing an external storage device in consideration of the respective characteristics of external storage devices of different types, and a data multiplex writing program. In providing a recording medium on which is recorded.

A second object of the present invention is to provide data multiplex writing capable of executing optimum multiplex writing such as to prevent an increase in the time required for multiplex writing to an external storage device of a different type or an increase in investment cost for the device. It is an object of the present invention to provide an apparatus and a method and a recording medium on which a data multiplex writing program is recorded.

A third object of the present invention is to provide a data multiplex writing apparatus and method capable of coping with the optimum execution of multiplex writing even in the event of a failure in some external storage devices, and to record a data multiplex writing program. In the provision of media.

[0011] Other objects of the present invention are as follows:
In particular, it will be obvious from the description of each claim in the claims.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a multiple write command section for issuing a multiple write command, and a control for selecting an external storage device to which the multiple write is to be performed and executing the multiple write. And a control unit, a memory storing management data of an external storage device used for selecting the multiple write destination, and a plurality of external storage devices of different types to be selected. And Further, the present invention is characterized in that a data multiplex writing method is used in which an optimum external storage device is selected by judging from performance information and status information in management data of the external storage device and multiplex writing is executed. Further, the present invention is characterized in that a recording medium of a data multiplex writing program, which is a recording medium in which a program of an execution processing procedure of the method in the device is recorded.

More specifically, in order to solve the above-mentioned problems, the present invention achieves the above object by adopting new characteristic constitution means or techniques ranging from a superordinate concept to a subordinate concept as listed below. Is done.

That is, a first characteristic of the present invention is that in a device for multiplex writing data to a plurality of external storage devices of different types, an external storage device group including a plurality of external storage devices, A memory for storing management data of the device, a multiplex write command unit for issuing a multiplex write command, and a control for selecting the external storage device for writing by referring to the management data in response to the command and executing multiplex write And a configuration of a data multiplex writing apparatus having the following components.

A second feature of the device of the present invention is that the external storage device group in the first feature of the above-described device of the present invention is a data multiplex writing device in which a plurality of external storage devices of the same type are configured for different types. In the configuration adoption.

A third feature of the device of the present invention is that the control unit according to the first or second feature of the device of the present invention is connected to each external storage device, multiple write command unit and memory. Configuration adoption.

A fourth feature of the device of the present invention resides in the adoption of a configuration of a data multiplex writing device in which the memory according to the first, second or third feature of the device of the present invention is connected to each external storage device. .

A fifth feature of the device of the present invention is that the management data in the first, second, third or fourth feature of the above-described device of the present invention expresses performance information and status information of each external storage device. The present invention resides in adoption of a configuration of a data multiplex writing device which forms a reference table.

A sixth feature of the device of the present invention resides in the adoption of a configuration of a data multiplex writing device in which the performance information in the fifth feature of the device of the present invention is information on the writing speed of each external storage device.

A seventh feature of the device of the present invention is that the status information in the fifth or sixth feature of the above-described device of the present invention is the current state of whether each external storage device is in a normal state in which it can operate or a failure state in which it cannot operate. The present invention lies in the configuration of a data multiplex writing device which is information.

An eighth feature of the device of the present invention resides in the adoption of a configuration of a data multiplex writing device in which the status information in the seventh feature of the device of the present invention has information on the remaining capacity of each external storage device. .

A ninth feature of the device of the present invention is that each external storage device in the first, second, third, fourth, fifth, sixth, seventh or eighth feature of the device of the present invention is Semiconductor files,
Any one of a magnetic disk, a magnetic tape, and the like,
The entire external storage device group employs a configuration of two or more types of data multiplex writing devices.

A first feature of the method according to the present invention is a method of performing multiplex writing of data to a plurality of external storage devices of different types, and judges management data relating to each external storage device in the external storage device group. An external storage device for performing multiple writing is selected by using this data as the data, and a multiple data writing method for executing multiple writing on the selected external storage device is adopted.

A second feature of the method of the present invention is that the external storage device group in the first feature of the above-described method of the present invention adopts a configuration of a data multiplex writing method comprising a plurality of external storage devices of the same type for each different type. It is in.

According to a third feature of the method of the present invention, the management data in the first or second feature of the method of the present invention is characterized in that the management data includes performance information indicating the performance of each external storage device and status information indicating the current status. The present invention resides in adopting a configuration of a multiple writing method.

A fourth feature of the method of the present invention resides in the adoption of the configuration of the data multiplex writing method in which the performance of the third feature of the present invention is the data writing speed.

A fifth feature of the method of the present invention resides in adoption of a configuration of a data multiplex writing method in which the performance information in the third or fourth feature of the method of the present invention is registered in advance before performing multiplex writing. .

A sixth feature of the method of the present invention is that the present state in the third, fourth, or fifth feature of the method of the present invention is such that a normal state in which each external storage device is operable, or an inoperable failure. It is in the configuration adoption of the data multiplex writing method which is a state.

A seventh feature of the method of the present invention resides in the adoption of a configuration of a data multiplex writing method in which the status information in the above-described sixth feature of the present method also represents the remaining capacity of each external storage device.

The eighth feature of the method of the present invention is that the status information in the third, fourth, fifth, sixth or seventh feature of the above-mentioned method of the present invention is obtained from each external storage device in a timely manner. The configuration of the data multiplex writing method is as follows.

A ninth feature of the method of the present invention resides in that the selection in the third, fourth, fifth, sixth, seventh or eighth feature of the above-described method of the present invention is such that each of the external states whose current state is a normal state is selected. In the storage device, the number of multiplexes or less as many as possible is performed only on the one with the highest performance, and if there is no applicable one, the number of multiplexes or the number of multiplexes on the next best performance only The present invention is based on the configuration of a data multiplex writing method in which the following operations are repeated as many times as possible.

A tenth feature of the method of the present invention is that the selection in the third, fourth, fifth, sixth, seventh or eighth feature of the method of the present invention is such that each of the external states whose current state is a normal state is selected. Of the storage devices, only the one with the highest performance is performed by the number of multiplexes, and if the number of multiplexes is not satisfied, only the next highest performance is performed until the number of multiplexes in the external storage device group as a whole is increased. The present invention resides in the adoption of a configuration of a data multiplex writing method which is repeated.

An eleventh feature of the method of the present invention resides in that the selection in the seventh, eighth, ninth or tenth feature of the method of the present invention is such that the write capacity is smaller than that of the external storage devices smaller than the remaining capacity. The present invention lies in the adoption of the configuration of the data multiplex writing method.

A twelfth feature of the method of the present invention is that the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, or eleventh of the above method of the present invention. In the adoption of the configuration of the data multiplex writing method in which the selection and the multiple writing in the feature of the above are repeatedly performed in order for each selection of one of the external storage devices and the writing to the selected one of the external storage devices. is there.

A first feature of the recording medium of the present invention is that, in a recording medium in which a program for performing multiplex writing of data to a plurality of external storage devices of different types is recorded, each external storage device in the external storage device group is stored in a memory. By appropriately obtaining status information indicating the current status of whether the device is in a normal state or a failure state from each of the external storage devices, performance information indicating the performance of the write speed of each of the external storage devices formed in advance and The state information is also combined and formed as management data of each of the external storage devices, and the multiplex write command unit transmits the multiplex write command to the control unit.
When fetching the management data on the memory and selecting the external storage device to be written, for one of the units having the best performance, letting the one in the normal state be written, If the number of multiplexes is less than or equal to the largest possible number, writing is performed in order, and if there is no applicable one, one of the next highest performance is written to the normal one. The present invention resides in adopting a configuration of a recording medium that records a data multiplex writing program in which multiplex writing is performed by repeatedly performing the same number of multiplexes or less multiplexes in order of as many as possible.

A second feature of the recording medium of the present invention is that, in a recording medium in which a program for performing multiplex writing of data on a plurality of external storage devices of different types is recorded, each external storage device in the external storage device group is stored in a memory. Performance information and status indicating the write speed performance of each of the external storage devices formed in advance by appropriately obtaining status information indicating the current status of whether the device is in a normal state or a failure state from each of the external storage devices. Information is also formed and stored as management data of each of the external storage devices, and the multiplex writing command unit transmits the multiplex writing command to the control unit, and the control unit obtains the management data on the memory. When selecting the external storage device to which the writing is to be performed, one of the devices having the best performance is written in the normal state. If the number of writes is less than the number of multiplexes, one of the next highest performance is written to the one in the normal state if the number of writes is less than the number of multiplexes. The present invention is to adopt a configuration of a recording medium which records a data multiplex writing program in which multiplex writing is performed by repeatedly performing the same operation until the number of multiplexes in the entire external storage device group reaches the number of multiplexes.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of an apparatus according to an embodiment of the present invention and an example of a method corresponding thereto will be described in order with reference to the accompanying drawings.

(Example of Apparatus) FIG. 1 is a block diagram showing a data multiplex writing apparatus according to this example of the apparatus. The example of this apparatus will be described with reference to FIG.

The data multiplex writing device A is provided in the computer system α. The data multiplex writing device A includes a multiplex writing command unit 1 that issues a multiplex writing command, a control unit 2 that selects the multiplex writing destination in the external storage device group 4 and executes the multiplex writing.
A memory 3 for storing its own management data in the external storage device group 4 used for selecting the multiple write destinations; semiconductor files 5a and 5b in the external storage device group 4 as external storage devices of different types; 6a and 6b. The management data includes performance information indicating the own data writing speed in the external storage device group 4 and status information indicating a normal state or a failure state.

The control unit 2 includes the multiple write command unit 1, the memory 3, and the semiconductor files 5a and 5b.
And the magnetic disks 6a and 6b. The memory 3 stores the semiconductor files 5a and 5b.
And the magnetic disks 6a and 6b.

Although the memory 3 and the external storage devices 5a to 6b of the external storage device group 4 are connected in the present example, the connection between the memory 3 and the control unit 2 is utilized without making the connection. Alternatively, the connection path between each external storage device and the memory 3 may be formed via the control unit 2.

In this embodiment, each of the external storage devices in the external storage device group 4 uses the semiconductor files 5a and 5b and the magnetic disks 6a and 6b, but may use a magnetic tape or the like.

(Example of Method) This example of the method corresponds to the above-described example of the apparatus, and will be described with reference to FIGS.

First, referring to FIG. 1, if there is a request for multiplex writing of data in the computer system α, the multiplex writing process is started in the data multiplex writing device A in the computer system α. The multiple write command is sent from the multiple write command unit 1 to the control unit 2.

Here, the memory 3 is a state which indicates at appropriate time whether the semiconductor files 5a, 5b and the magnetic disks 6a, 6b of the respective external storage devices in the external storage device group 4 are in a normal state or a faulty state. Information is collected in advance, and the state information is rewritably written in the memory 3 and registered. The state information and data of the external storage devices 5a to 6b registered and stored in the memory 3 in advance are stored. Management data with performance information indicating the performance of the writing speed is registered and stored in the memory 3.

Table 1 below shows an example of the semiconductor files 5a and 5a as an example of a management data comparison table T.
b indicates a case where both of the magnetic disks 6a and 6b are in a normal state, and indicates management data in a case where both of the magnetic disks 6a and 6b are in a normal state. It is stored on the memory 3.

[Table 1]

From the management data including the performance information and the status information, one of the external storage devices 5a to 6b to be subjected to multiplex writing in the external storage device group 4 is selected by a determination process. The writing is executed to one of the external storage devices 5a to 6b selected from the determination processing, and the selection and the writing execution are repeated, thereby completing the multiple writing processing.

Next, referring to FIG. 2, a description will be given of a method of multiplex writing by repetition of the selection and the writing in the control unit 2 in this example of the method.
FIG. 2 is a diagram illustrating a flowchart of an execution procedure of the multiple writing process according to the example method.

First, the control unit 2 obtains the management data from the memory 3 and starts a multiple writing process.

First, it is determined from the status information in the management data whether a semiconductor file in a normal state exists (step S1). If the semiconductor file 5a corresponds to step S1, the semiconductor file 5a is determined to be normal. It is determined whether the state is the state (step S2).
If the above applies, the semiconductor file 5a is selected and data is written (step S2a).

When the condition does not correspond to the step S2 or when the step S2a is completed, it is determined whether the semiconductor file 5b is in a normal state (step S2).
3) If it corresponds to step S3, the semiconductor file 5b is selected and data is written (step S3a).

If the condition does not correspond to step S1, it is determined whether the magnetic disk 6a is in a normal state (step S4). If the condition corresponds to step S4, the magnetic disk 6a is selected and data is stored. Is written (step S4a).

When the condition does not correspond to step S4 or when step S4a is completed, it is determined whether the magnetic disk 6b is in a normal state (step S4).
5) If it corresponds to step S3, the magnetic disk 6b is selected and writing is performed (step S5).
a).

If it does not correspond to the step S3, if the step S3a is completed, if it does not correspond to the step S5, or if it corresponds to the case where the step S5a is completed, the multiplex writing process is ended. .

In the multiple writing process, when both the semiconductor files 5a and 5b are in a normal state, high-speed double writing is performed on the semiconductor files 5a and 5b, and the management of the comparison table T shown in Table 1 is performed. When both of the semiconductor files 5a and 5b as an example of data are in a failure state and both of the magnetic disks 6a and 6b are in a normal state, low-speed double writing is performed on the magnetic disks 6a and 6b. Therefore, the reliability of data is increased by storage in the same type of external storage device, the required time for writing is unified, and the required time for multiplex writing of data is also reduced. You.

When there is one semiconductor file 5a or 5b in the normal state, high-speed writing is performed only on the single semiconductor file 5a or 5b, and writing is not performed on the magnetic disks 6a and 6b in the normal state. The required time is unified by writing in one type of external storage device. The required time is unified, and the required time is shortened.
Therefore, no new investment cost for shortening the required time is required.

On the other hand, with further emphasis on the increase in the reliability,
Except when only one of the external storage devices 5a to 6b is in a normal state, double writing is always performed, and writing is performed when only one semiconductor file 5a or 5b is in a normal state. Alternatively, double writing may be performed by writing to one of the magnetic disks 6a or 6b in a normal state.

Therefore, even when some of the external storage devices 5a to 6b in the group of external storage devices 4 are in the failure state, the required time can be unified or the reliability can be increased. It can respond flexibly.

As described above, in this embodiment, multiplex writing to the external storage device is performed as double writing. However, the number of multiplexing is tripled, quadruple or more by adding an external storage device or the like. Is performed, it is easy to further increase the reliability of the stored data.

Further, the type of each external storage device is not limited to two types. Even when the types are two or more types, the performance of the external storage device is the best for each device in the normal state. Select and write only the number of multiplexes or as many as possible or less as many as possible, and if there is no applicable one, only the next best performance and the number of multiplexes or less as many as possible. If the embodiment in which selection and writing are repeated is performed, the performance (required time) is unified and the reliability is increased, and the number of multiplexes can be set within the number of external storage devices of the same type.

Alternatively, when the reliability is further increased when there are two or more types, only those having the best performance are compared with those in a normal state of a plurality of external storage devices.
An embodiment in which selection and writing are performed by the number of multiplexes, and if the number of multiplexes is not satisfied, selection and writing are repeated until the number of multiplexes of the entire external storage device group is reduced to only the next highest performance. Is performed, the reliability is further increased, and the number of multiplexes can be increased in accordance with the number of external storage devices.

Therefore, the time required for multiple writing can be reduced,
It can be easily applied to usage modes according to purposes, such as increasing the reliability of stored data.

In addition, if the state information has information on the remaining capacity of each external storage device, and the remaining capacity is smaller than the writing capacity, selection of the corresponding external storage device and execution of writing are performed. It is naturally conceivable not to do this.

[0064]

Next, a specific example based on the above-described apparatus and method according to an embodiment of the present invention will be described.
Configure a program of the execution processing procedure of the method example in the device example, and record the program in a recording medium,
The recording medium is set inside and outside of the computer system α in the example of the apparatus, and the actual operation procedure of the data multiplex writing process is executed by reading and executing the program.

The types of the recording medium include a ROM, a semiconductor file, a magnetic disk, a flexible disk, a magneto-optical disk, a DVD, a magnetic tape, a CD, and the like. Therefore, the program is stored in advance in the semiconductor files 5a and 5b as the external storage device in the device example,
a, 6b or the memory 3.

(Recording Medium Example 1) This recording medium example is a recording medium in which a program for performing multiplex writing of data in a plurality of external storage devices of different types is recorded.
Then, status information indicating the current status of each external storage device in the external storage device group 4 in a normal state or a failure state is obtained in a timely manner from each of the external storage devices 5a to 6b, and each external storage device The performance information indicating the performance of the writing speed of the storage devices 5a to 6b and the status information are combined and formed as management data of each of the external storage devices 5a to 6b. Control unit 2
When the control unit 2 obtains the management data on the memory 3 and selects the external storage device to which the data is to be written, one of the units having the best performance is set to the one in the normal state. The writing is performed in the order of the number of multiplexes or less as large as possible in the order of the same performance, and if there is no applicable one, the one with the next best performance is A series of the above-described series of steps of causing a normal state to be written, by repeatedly performing, for those having the same performance, the order of the number of multiplexes or as many as possible as much as possible, to perform multiplex writing. Is recorded on a recording medium using an appropriate program language readable by the computer system α.

(Recording Medium Example 2) This recording medium example is a recording medium in which a program for performing multiplex writing of data in a plurality of external storage devices of different types is recorded.
Then, status information indicating the current status of each of the external storage devices 5a to 6b in the external storage device group 4 in a normal state or a failure state is sent to each of the external storage devices 5a to 6b in a timely manner.
The performance information indicating the performance of the writing speed of each of the external storage devices 5a to 6b formed in advance and the status information are combined together.
It is formed and stored as management data of each of the external storage devices 5a to 6b, and the multiplex writing command unit 1 transmits the multiplex writing command to the control unit 2, and the control unit 2 obtains the management data on the memory 3. When selecting the external storage device for writing, the one with the best performance 1
With respect to the group, the writing in the normal state is performed in order by the number of multiplexes for those having the same performance, and if the number of writes is less than the number of multiplexes, the performance is not satisfied. Multiplexing is performed by causing the next good device to be written to the normal device in the normal state until the number of multiplexes in the external device group 4 as a whole is repeated for those having the same performance. The above-described series of operation procedures to be written are recorded on a recording medium using an appropriate program language readable by the computer system α.

As described above, the embodiments and examples of the present invention have been described. However, the present invention is not necessarily limited only to the above-described means and methods, and achieves the object of the present invention and realizes the present invention. The present invention can be appropriately changed and implemented within a range having the above-mentioned effects.

[0069]

As described above, according to the present invention,
In multiplex writing to a plurality of external storage devices of different types, when selecting an optimum external storage device from the characteristics of each external storage device, selection of a high-speed external storage device is preferentially performed. The time required until the end of the processing is shortened.

Further, since the required time is unified by multiple writing in the same type of external storage device, the required time for the multiple writing process of data is shortened and the reliability is increased at the same time. In addition, even when some of the external storage devices in the external storage device group are in a failure state, the required time can be unified, and no new investment cost for reducing the required time is required.

On the other hand, by permitting multiplex writing between external storage devices of different types, the reliability of the stored data can be further increased, and the application to the device and method of use according to the purpose can be facilitated. It can be carried out.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a data multiplex writing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a flowchart of a procedure of a multiplex writing process in FIG. 1;

[Explanation of symbols]

 α: Computer system A: Data multiplex writing device 1: Multiple writing command unit 2: Control unit 3: Memory 4: External storage device group 5a, 5b: Semiconductor files 6a, 6b: Magnetic disk

Claims (23)

[Claims] An apparatus for multiplex writing data to a plurality of external storage devices of different types, comprising: an external storage device group including a plurality of external storage devices; a memory for storing management data of each of the external storage devices; A multiple write command unit that issues a multiple write command, and a control unit that receives the command, refers to the management data, selects the external storage device that performs the write, and executes the multiple write. Data multiplex writing device. 2. The data multiplex writing apparatus according to claim 1, wherein the external storage device group comprises a plurality of external storage devices of the same type for each different type. 3. The data multiplex writing device according to claim 1, wherein the control unit is connected to each of the external storage devices, the multiplex writing command unit, and the memory. 4. The data multiplex writing device according to claim 1, wherein the memory is connected to each of the external storage devices. 5. The data multiplexing method according to claim 1, wherein the management data forms a comparison table in which performance information and status information of each of the external storage devices are described. Writing device. 6. The data multiplex writing apparatus according to claim 5, wherein the performance information is information on a writing speed of each of the external storage devices. 7. The data multiplexing method according to claim 5, wherein the status information is current status information indicating whether each of the external storage devices is operable in a normal state or inoperable failure state. Writing device. 8. The data multiplex writing apparatus according to claim 7, wherein the status information includes information on a remaining capacity of each of the external storage devices. 9. The external storage device may be any one of a semiconductor file, a magnetic disk, a magnetic tape, and the like.
The data multiplex writing apparatus according to claim 1, 2, 3, 4, 5, 6, 7, or 8. 10. An external storage device that performs multiplex writing by using management data relating to each external storage device in the external storage device group when performing multiplex writing of data to a plurality of external storage devices of different types. And performing multiplex writing on the selected external storage device. 11. The data multiplex writing method according to claim 10, wherein said external storage device group comprises a plurality of external storage devices of the same type for different types. 12. The data multiplex writing method according to claim 10, wherein the management data comprises performance information indicating the performance of each of the external storage devices and status information indicating a current status. 13. The data multiplex writing method according to claim 12, wherein said performance is a data writing speed. 14. The data multiplex writing method according to claim 12, wherein the performance information is registered in advance before performing the multiplex writing. 15. The data multiplexing method according to claim 12, wherein the current state is a normal state in which each of the external storage devices is operable or a failure state in which each of the external storage devices is inoperable. Writing method. 16. The data multiplex writing method according to claim 15, wherein said status information also indicates a remaining capacity of each of said external storage devices. 17. The system according to claim 12, wherein the status information is obtained by obtaining the status information from each of the external storage devices in a timely manner.
7. The data multiplex writing method according to item 6. 18. The method according to claim 18, wherein the selection is performed only on the one with the best performance among the respective external storage devices whose current status is normal, by the number of multiplexes or by the maximum possible number or less. 17. The method according to claim 12, wherein if there is no operation to be performed, the operation with the next highest performance is repeated as many times as possible or as many as possible.
Or the data multiplex writing method according to 17. 19. The method according to claim 19, wherein, among the external storage devices in which the current status is normal, the number of multiplexes is determined only for the device having the best performance, and if the number of multiplexes is not satisfied, 17. The method according to claim 12, wherein the step of repeating the above operation is repeated until the number of multiplexes in the entire external storage device group becomes equal to the next highest performance.
Or the data multiplex writing method according to 17. 20. The data multiplex writing method according to claim 16, wherein the selection is performed from among the external storage devices whose writing capacity is smaller than the remaining capacity. 21. The method according to claim 21, wherein the selection and the multiplex writing are repeatedly performed in such a manner that writing to one of the selected external storage devices is sequentially performed for each selection of one of the external storage devices. Claims 10, 11, 12, 13, 1
The data multiplex writing method according to 4, 15, 16, 17, 18, 19, or 20. 22. A recording medium in which a program for multiplex writing data to a plurality of external storage devices of different types is recorded, wherein each external storage device in the external storage device group is in a normal state or a faulty state in a memory. The status information indicating the current status is obtained from each of the external storage devices in a timely manner, and the performance information indicating the performance of the writing speed of each of the external storage devices formed in advance and the status information are added together. It is formed and stored as management data of an external storage device, and the multiplex writing command unit transmits the multiplex writing command to the control unit. The control unit obtains the management data on the memory and writes the external data. When choosing a storage device,
For one of the units having the best performance, the one in the normal state is written, and for the one having the same performance, writing is performed in order of the number of multiplexes or the largest possible number less than that. If there is no such thing, for the one with the next highest performance, writing to the one in the normal state is performed in order of the number of multiplexing or the largest possible number less than that for the one with the same performance. A recording medium on which a data multiplex writing program is recorded, wherein the multiplex writing is performed by repeating the writing. 23. A recording medium in which a program for multiplex writing data to a plurality of external storage devices of different types is recorded, wherein each external storage device in the external storage device group is in a normal state or a faulty state in a memory. The status information indicating the current status is obtained from each external storage device in a timely manner, and the performance information indicating the write speed performance of each external storage device that has been formed in advance and the status information are added together. The external storage device is formed and stored as management data of the external storage device, and the multiplex writing command unit transmits the multiplex writing command to the control unit. The control unit retrieves the management data on the memory and writes the external data. When selecting a storage device, for one of the units having the best performance, letting the one in the normal state be written into has the same performance. Made to perform in order for the number of multiplexing for the, unless if less than the number the number of said multiple of said writing,
For one of the devices having the next highest performance, the writing to the device in the normal state is repeated for the devices having the same performance until the number of multiplexes in the entire external device group is increased. A recording medium on which a data multiplex writing program is recorded.