JPH09330261A - Data backup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform optimum data backup in accordance with the character of a backup object. SOLUTION: This data backup device 1 is provided with a 1st backup part (a) for recording all the updated data into a backup medium 3, a 2nd backup parts (b) and for (b') recording only the data changed by updating work from the time of last backup end into the backup medium 3, a backup quantity estimation part 4 for recognizing the change amount of data from the end of the last backup, and a election part 5 for selecting the 1st backup part (a) when the recognized change amount of data is more than a prescribed amount and selecting the backup of data due to the 2nd backup parts (b) and (b') when the change amount of data is less than the prescribed amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data backup device that automatically backs up files created by a computer.

[0002]

2. Description of the Related Art Conventionally, in a data backup device used in a LAN environment or the like, a user sets an appropriate plan for carrying out a backup for each target and inputs it into the data backup device. The data backup device appropriately backs up the data.

For example, if data is frequently updated or highly important data is set, backup is set to be performed in a short period of time, and if the data update amount is small or less important data is set. In case of, the backup is set after a long period of time.

[0004]

However, the appropriate backup plan differs depending on the nature of the backup target, and if a plan that does not match the target nature is erroneously input to the data backup device. However, this is uneconomical because it increases the time and the amount of media required for backup and restoration.

Further, in an actual LAN environment, there are many backup targets having various properties, and it is very difficult for the user to make a backup execution plan according to these backup targets. In addition, the amount of data update and the update period are constantly changing, and it is difficult for the user to determine the optimal backup plan at that time and maintain an appropriate plan.

[0006]

The present invention is a data backup device made to solve the above problems. That is, the present invention is a data backup device that records the data that is being updated on a backup medium after a predetermined period has elapsed, and a first backup unit that records all the data that has been updated on a backup medium. A second backup means for recording only the data that has changed due to the update work since the end of the previous backup on the backup medium, a change amount recognition means for recognizing the change amount of the data since the end of the previous backup, and a change amount. If the amount of change in the data recognized by the recognizing unit is equal to or larger than a predetermined amount, the backup of the data by the first backup unit is selected, and if the amount of change in the data is less than the predetermined amount, the second backup unit is selected. Backup control means for selecting the backup of data according to. Further, the change amount recognizing means also recognizes the amount of change in data from the end of the backup by the first backup means.

Further, the backup means for backing up the data changed from the predetermined reference time, the recognizing means for recognizing the data amount of one backup by the backup means, and the backup data amount recognized by the recognizing means are In the case of a predetermined amount or more, the data backup device is also provided with a reference time point changing means for setting a new reference time point at the end of the backup. Further, the recognition means also recognizes the cumulative total of the amount of data backed up by the backup means from the reference time point.

According to the present invention, there is provided a first backup means for backing up all of the updated data and a second backup means for backing up only the change from the end of the previous backup, and the change of data is provided. The amount of change is recognized by the change amount recognition means, and based on the recognition result, the backup control means selects the optimum backup means whether to perform the backup by the first backup means or the second backup means. There is.

Further, in the data backup device provided with the backup means for backing up the data that has changed from the predetermined reference time, the data amount of one backup by the backup means by the recognition means and the backup means from the reference time. The accumulation of the amount of data backed up is recognized, and the reference time point changing means changes the reference time point of the backup based on the recognized amount of backup data.

By controlling the change of the backup reference time point, it becomes possible to set the optimum backup timing based on the backup data amount.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a data backup device of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram illustrating an embodiment of a data backup device of the present invention. When the data stored in the disk 2 is updated, the data backup device 1 records the data in a backup medium 3 such as a floppy disk after a predetermined period of time.

The data backup apparatus 1 according to the present embodiment has a first backup section a for recording all the data for which the data updating work has been performed on the backup medium 3, and a change due to the updating work after the last backup is completed. A second backup unit (No. 1) b for recording only the existing data on the backup medium 3 and a second backup unit (No. 2) b'for backing up the data that has changed due to the update work from a predetermined reference time point. I have it.

The data backup device 1 further includes a backup amount estimation unit 4 for estimating the amount of data to be backed up by a predetermined calculation, and a first backup unit a and a second backup unit based on the calculation result by the backup amount estimation unit 4. There is provided a selection unit 5 for selecting an optimum one from the part (1) b and the second backup (2) b ′.

Here, the first backup section a, the second backup section (No. 1) b, the second backup (No. 2)
Data backup by each backup unit b'will be described. First, in the first backup unit a, every time backup is performed, all of the updated data (including not only the updated portion but also the unupdated portion) is recorded in the backup medium 3.

When the backup is performed in the first backup section a, the amount of data to be recorded is larger than that in the other backup sections (second backup sections (1) and (2)). The number of times until the original data is restored using this backed up data is small.

In the second backup section (No. 1) b, only the data changed by the update work after the previous backup is finished is recorded in the backup medium 3, and the second backup section (No. 2) b is recorded. In ', the data that has changed due to the update work from the predetermined reference time is recorded in the backup medium 3.

FIG. 2 is a schematic diagram for explaining the backup standard. For example, when the current time is n, when performing backup by the second backup unit (No. 1) b, only the changed data is recorded with reference to the end time n-1 of the previous backup. On the other hand, when backup is performed by the second backup unit (part 2) b ′, a preset reference time point (n−2 in the example of FIG. 2)
Record the data that has changed from.

Therefore, when backup is performed in the second backup section (1) b, the backup data amount is the smallest as compared with other backups, but the number of restorations to the original data is the largest. Become.
That is, since only the data up to the previous time can be restored by the restoration using the backup file once, the restoration work is required as many times as the number of backups to restore the original data.

The second backup section (2) b '
When the backup is performed in step 1, the backup data amount is smaller than the backup amount in the first backup part a, but is larger than the backup amount in the second backup part (part 2) b. On the contrary, the number of times of restoration to the original data is larger than that of the backup in the first backup section a, but less than that of the second backup section (No. 1) b.

FIG. 3 is a schematic diagram for explaining the backup amount in each backup unit. FIG. 3A shows a state in which the addition S ₁ , the change H ₁ , and the deletion D ₁ are performed by the _first update work on the original data, that is, the original OR, and in FIG. A state in which addition S ₂ , modification H ₂ , and deletion D ₂ are performed by the _second update work on the state K ₁ after the second update is shown. FIG. 3 (c)
Then, the original OR state and the state after the second update K ₂
And are overlaid.

When such an update is performed, in the backup in the second backup section (1) b, first, after the first update, the additional S ₁ in the state K ₁ after the _first update is added. + Back up the part of change H ₁ . Then, after the second update, the portion of the additional S ₂ + change H _{2 in} the state K ₂ after the second update is backed up.

On the other hand, the second backup section (2) b '
Backup, as shown in FIG. 3 (c),
Additional S ₂ + by the second update to the original OR
The part of the change H ₂ and the remaining part S ₁ ′ of the _first addition S ₁ + the remaining part H ₁ ′ of the _first change H ₁ are backed up.

FIG. 4 is a schematic diagram for explaining the difference in backup amount. (A) is the backup amount in the second backup section (part 1) b performed after the first update shown in FIG. 3, (b) ) Is the backup amount in the second backup unit (1) b performed after the second update shown in FIG.
(C) is the backup amount in the second backup unit (part 2) b ′ performed after the second update shown in FIG.

As described above, the backup amount of each one-time backup is larger in the second backup unit (No. 2) b ′ than in the second backup unit (No. 1) b. .

In the present embodiment, in consideration of such a backup amount and the labor required for restoration, the selecting unit 5 shown in FIG. 1 selects the most suitable backup unit, and the most economical backup of the data at that time is made. There is a feature in doing it.

Next, the selection process in the selection unit will be described with reference to the flowchart of FIG. In the flowchart shown in FIG. 5 and the following description, it is assumed that the first backup unit is a, the second backup unit (No. 1) is b, and the second backup unit (No. 2) is b '. Further, N represents the number of backups by b since the last backup by a was performed. If no backup by a has ever been performed, N is set to −1. ing. A predetermined upper limit value is set for this N.

Further, S _a shown in FIG. 5 is a backup amount according to a estimated by the backup amount estimation unit 4 shown in FIG. 1, S _b is a backup amount according to b estimated by the backup amount estimation unit 4, and S _{b ′} is It is the backup amount according to b ′ estimated by the backup amount estimation unit 4.

First, as shown in step S101, N
It is determined whether or not = 0. If N is not 0 here, the process proceeds to step S102, and it is determined whether N = -1. If N = -1, it means that the backup by a has not been performed even once, so step S
Proceed to 103 to adopt backup by a.

If N = 0 in the determination in step S101, the process proceeds to step S104 to determine whether S _a > 2S _b . If the result is Yes, the process proceeds to step S105 and the backup by b is adopted, and if the result is No, the process proceeds to step S103 and the backup by a is adopted.

In consideration of the balance between the consumption amount of the backup medium 3 and the labor required for restoration, the backup by a and the backup by b have a relatively small amount of change in data due to updating (amount of backup by b). In this case, priority is given to saving the consumption of the backup medium 3b
This is because the backup according to step (a) is adopted, and when the amount of change in data due to updating (the amount of backup according to step (b)) is relatively large, the backup due to step (a) is preferentially adopted for the one with less trouble of restoration.

Next, when the value of N is neither "0" nor "-1", the process proceeds to step S106, and it is determined whether N = upper limit. If N is not the upper limit, the determination is No and the process proceeds to step S107 to determine whether S _a > 2S _b . If the determination in step S107 is no, the process proceeds to step S108 and the backup by a is adopted.

On the other hand, if the result of the determination in step S107 is Yes, the process proceeds to step S109 and S _{b '} > 2S _b
Is determined. If the determination is Yes, the process proceeds to step S110, and the backup medium 3
The backup by b is adopted with priority on saving the consumption amount of. If the result of the determination in step S109 is No, the process proceeds to step S111, and the backup by b ′ is adopted by giving priority to the one having less trouble in data restoration.

If N = upper limit is determined in step S106, the process proceeds to step S112, where S _a > 2S
Determine whether it is _{b '} . If the result of this determination is Yes, the process proceeds to step S113, and the backup by b ′ is adopted with priority on saving the amount of consumption of the backup medium 3. On the other hand, if No, step S10
Go to 3 and give priority to the one with the least effort to restore the data a
Adopt backup by.

By such processing, it becomes possible to select an optimum backup in consideration of the balance between the consumption amount of the backup medium 3 and the trouble of restoring the data.

In the embodiment described above, step S104 and step S1 of the flowchart shown in FIG.
07, step S109, step S112,
The right side of the inequality sign (>) is multiplied by the constant "2", respectively,
The present invention is not limited to “2”, and may be set appropriately according to the property of data.

Next, another embodiment of the present invention will be described with reference to the schematic view of FIG. In FIG. 6, as an example of backup, the data amount of backup with respect to the progress of backup by a, backup by b, and backup by b ′ is shown.

For example, in the backup shown in FIG. 6, first, the entire data is recorded by the backup by a, and then the backup by b is performed after the backup performed after a. After that, backup by b ′ is performed several times, and after a predetermined number of times, backup by b is performed again. Then, after repeating the backup by b and b ′ several times, the backup by a is performed.

In another embodiment, in performing such backup, the backup amount estimating unit 4 shown in FIG. 1 determines whether the backup by b'is performed after the backup by b. It is characterized in that the selection unit 5 makes a selection based on the performed quantitative calculation.

There are the following two types of quantitative calculations in the backup amount estimation unit 4. First, first
As the calculation of b, the data amount of one backup by b'is calculated each time, and when the data amount becomes more than a predetermined value, the end time of the backup by b'is set as a new reference time. Back up by b based on the time point. After that, the backup by b'is performed based on the new reference time set previously.

This first calculation is effective when the amount of data in each backup by b and b'is almost constant, and after backup by b once, backup by b's several times. The fact that the cumulative amount of data recorded in step 1 can be predicted when the amount of data backed up by b ′ once exceeds a predetermined value is used.

As a result, it becomes possible to perform the backup by b again when the data amount of the backup by b once + the backup by b's several times reaches the predetermined amount.

The second calculation is to calculate the cumulative amount of backup data for b's several times from the amount of backup data for one b, and if the cumulative amount of data exceeds a predetermined value. In addition, the end time of the backup by the latest b ′ is set as a new reference time point, and the backup by b is performed based on this reference time point. After that, the backup by b'is performed based on the new reference time set previously.

This second calculation is effective when the amount of data in each backup by b and b'is not constant.

In both the first calculation and the second calculation, the backup group consisting of one backup b and several b'backups is repeated several times, and then backup a again. Set whether to perform. By such a calculation, it becomes possible to perform the most economical backup in consideration of the balance between the consumption of the backup medium 3 and the trouble of restoring the data.

In the second calculation described above,
From the amount of data backed up by b once, b'of several times
The following specific settings are conceivable as the predetermined value to be compared with the cumulative value of the backup data amount.

That is, during the backup by a,
Backup by one b and several b '(hereinafter,
Backup group. ) Is performed t times, the predetermined value = 1 data amount of backup by a once / t.

That is, the amount of data to be backed up by one time a is the total amount of data to be backed up, and a value obtained by dividing this by the number of times t of the backup group is set as a predetermined value.

For example, when the backup group of b and the b'of several times is performed four times while the backup of a is performed, a value obtained by dividing the data amount of the backup of one a by 4 is set as the predetermined value. (Value of 1/4 of the data amount of backup by one time of a) is set.

As a result, the cumulative value of the amount of data in the backup group is 4 times the amount of data for one backup of a.
When it becomes 1 / or more, the backup by the next backup group is performed. By setting such a predetermined value, the balance between saving the consumption of the backup medium 3 and the number of data restorations is optimized.

[0050]

As described above, the data backup device of the present invention has the following effects. That is, the present invention comprises a first backup means for backing up all of the data and a second backup means for backing up only the data that has changed since the end of the previous backup. Since the backup means is automatically selected by accumulating data, it is possible to achieve both saving of the consumption of the backup medium and suppression of the number of times until the data is restored.

As a result, it becomes possible to save the user the trouble of selecting a backup method, and it is possible to perform the most appropriate data backup at that time.

[Brief description of drawings]

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

FIG. 2 is a schematic diagram illustrating a backup standard.

FIG. 3 is a schematic diagram illustrating a backup amount.

FIG. 4 is a schematic diagram illustrating a difference in backup amount.

FIG. 5 is a flowchart illustrating a selection process.

FIG. 6 is a schematic diagram illustrating another embodiment.

[Explanation of symbols]

 1 data backup device 2 disk 3 backup medium 4 backup amount estimation unit 5 selection unit a first backup unit b second backup unit (No. 1) b'second backup unit (No. 2)

Claims (5)

[Claims] 1. A data backup device for recording data for which update work has been performed on a backup medium after a predetermined period has elapsed, a first backup means for recording all of the data for which update work has been performed on the backup medium, Second backup means for recording only the data that has changed due to the updating work to the backup medium since the end of the previous backup; and a change amount recognition means for recognizing the change amount of the data since the end of the previous backup. If the change amount recognized by the change amount recognizing unit is equal to or more than a predetermined amount, the backup of the data by the first backup unit is selected, and if the change amount is less than the predetermined amount, the second backup is selected. Backup control means for selecting the backup of data by the backup means of Data backup apparatus characterized by there. 2. A data backup device for recording data for which update work has been performed on a backup medium after a lapse of a predetermined period, first backup means for recording all of the data for which update work has been performed on the backup medium, A second backup unit that records only the data that has changed due to the update operation to the backup medium since the end of the previous backup, and a change that recognizes the amount of change in the data from the end of the backup by the first backup unit. When the amount of change recognized by the amount recognition unit and the amount of change recognition unit is greater than or equal to a predetermined amount, the backup of the data by the first backup unit is selected, and the amount of change is less than the predetermined amount. Is a bar for selecting the data backup by the second backup means. Data backup apparatus characterized by and a backup control unit. 3. Backup means for backing up data that has changed from a predetermined reference time point, recognition means for recognizing the data amount of one backup by the backup means, and backup data recognized by the recognition means. A data backup device comprising: a reference time point changing means for setting a new reference time point at the end of the backup when the amount is a predetermined amount or more. 4. A backup means for backing up data that has changed from a predetermined reference time point, a recognition means for recognizing the total amount of data backed up by the backup means from the reference time point, and a recognition means for recognizing the accumulated data amount. The data backup device further comprises a reference time point changing means for setting a new reference time point when the latest backup is completed when the backup data amount is a predetermined amount or more. 5. The data backup device according to claim 4, further comprising setting means for setting the maximum value of the number of backup data required for data restoration, and data amount for recognizing the total amount of data to be backed up. A recognition unit; and a calculation unit that calculates a value obtained by dividing the data amount recognized by the data amount recognition unit by the number set by the setting unit, and the predetermined amount by the value calculated by the calculation unit. A data backup device characterized by being.