JPH03224040A - File saving system and saving restoration system - Google Patents

Abstract

PURPOSE:To reduce the saving quantity of blocks by storing the updating information and the ID of an updated block into a history file at every updating operation and saving only the blocks having their IDs and stored in the history file into a saving file at the time of saving. CONSTITUTION:A saving means 9 saves totally a data file 1 into a saving file 4 in preparation for the fault of an external storage device 2 storing the file 1. Then an updating means 9 updates the file 1 and a history output means 7 outputs the updating information and the ID of the updated block to a history file 3. When the updating job is ended, a history retrieving means 8 retrieves the file 3 to obtain a stored block ID. The means 9 saves only the block that has the block ID obtained by the means 8 into the file 4. Thus the saving quantity of blocks can be reduced without delaying the updating processing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a file saving method and a saving and restoring method for saving and saving and restoring data files in a computer system.

[Conventional technology]

BACKGROUND ART It has been conventional practice to save data files in case an external storage device storing data files fails. By the way, when saving data files, there is a method of saving all data files, but since this method requires a large amount of data to be saved, only a part of the data file to be saved is set as an updateable area, and the file A method has also been proposed in which only data records in updatable areas are saved at the time of saving.

Note that when updating a data record in a non-updatable area, the data record is moved to an updatable area and then updated.

[Problem to be solved by the invention]

According to the conventional method of saving only the data records in the updatable area, it is possible to reduce the amount of saving, but when updating data records in the non-updatable area, the data records are saved in the updatable area. There is a problem that the update process is slow because the update process has to be moved to .

An object of the present invention is to reduce the amount of data to be saved without slowing down update processing.

[Means to solve the problem]

In order to achieve the above object, the present invention includes: a data file stored in an external storage device; an update means for performing update processing on the data file; and update information and updates by the update means updating the data file. Block I of the block that performed
a history output means for outputting D to a history file; a history search means for obtaining a block ID stored in the forward history file at the time of evacuation; and a history search means for saving the block having the block ID found by the history search means to the evacuation file. It is equipped with evacuation means.

Further, in order to restore the data file, the present invention is provided with a restoring means for restoring the data file based on the contents of the save file and the contents of the history file.

(for production) The update means performs update processing on the data file.

The history output means outputs update information and the block ID of the updated block to the 7-history file when the update means performs update processing on the data file. The history search means finds the block ID stored in the history file at the time of saving, and the saving means saves the block having the professional ID found by the history search means to the save file. The restoring means restores the data file based on the contents of the save file and the contents of the history file at the time of restoration.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, which includes an external storage device 2 storing a data file 1, a history file 3, a save file 4, an updating means 6 for updating the data file 1, and When the update means 6 updates the data file 1, the file system 5 includes a history output means 7 that outputs the update information and the block ID (identifier) of the updated block to the history file 3; It is composed of a history search means 8 for finding the block ID of a block, a saving means 9 for carrying out saving processing, and a restoring means 10 for carrying out restoring processing. Here, a block is a unit for inputting and outputting the data file 1, and a block ID is an identifier for uniquely identifying a block.

Figure 2 shows an example of the operation when saving data files, Figure 3
The figure is an explanatory diagram of an example of the operation when restoring a data file, and the operation of this embodiment will be explained below with reference to each figure.

First, the process at the time of evacuation will be explained.

In preparation for a failure of the external storage device 2 storing the data file 1, the entire data file 1 is saved to the save file 4 by the save means 9 at the first appropriate opportunity (#a in FIG. 2). Thereafter, the updating means 6 performs an updating operation A1 on the data file 1. Renewal business FIAI
When updating the data file 1, the update means 6 activates the history output means 7 in order to restore the updated contents or to output history information to the history file 3 in preparation for recovery after a failure occurs. . When activated, the history output means 7 outputs update information and the block ID of the updated block to the history file 3.

When the update task A1 is completed, the history search means 8 and the save means 9 perform update block save processing A2. In the updated block saving process A2, the history search means 8 searches the history file 3 to obtain the stored block ID, and the saving means 9 searches the history file 3 for the stored block ID, and the saving means 9 searches the history file 3 for the stored block ID,
Only the blocks having the block ID determined by the history search means 8 are saved in the save file (#b in FIG. 2). still,
When searching the history file 3, the history search means 8 searches only the portion of the history file 3 where update information and block IDs have been stored since the previous save process (updated block save process or save process of the entire data file l). Search for.

Therefore, by performing the update process A2, the blocks updated after the entire save #a are saved to the save file 4.

When the update block saving process A2 is completed, the update unit 6 performs an update operation fMB1. In the update task B1, the same processing as in the update task A1 is performed, and the update information and the block ID of the updated block are stored in the history file 3.

When the update task B1 is completed, the history search means 8 and the save means 9 perform update block save processing B2. In the updated block saving process B2, the same process as the updated block saving process A2 is performed, and after the updated block saving process A2 is performed in the saved file 4, the updated block is saved (#c in FIG. 2). ).

Next, the operation at the time of restoration will be explained with reference to FIG.

When a failure occurs in the external storage device 2, the external storage device 2 is first restored (Sl), and then the restoring means 10 is activated. When the restoration means 1o is activated, the backup file 4
By returning the entire data file 1 that was first saved to data file 1, data file 1 is restored to its initial state (S2), and then the blocks are saved in the order in which they were saved to save file 4 in the update block save process. By returning to file 1, data file 1 is restored to the state at the time of the latest updated block save processing (S3), and finally, based on the contents of history file 3, the contents of data file 1 are restored to the state at the time of failure. Restore to (S
4).

〔Effect of the invention〕

As explained above, the present invention stores update information and the block ID of the updated block in a history file every time an update is performed by the update means, and when saving, the block ID of the updated block is stored in the history file. Since only the programs having the block ID of the current block ID are saved to the save file, the amount of save can be reduced without slowing down the update process. Moreover, furthermore,
The present invention is equipped with a restoration means for restoring a data file based on the contents of the save file and the contents of the history file, so when a failure occurs in the external storage device, the update process is not slowed down and the amount of backup is reduced. It has the effect of restoring data files with a small amount of data.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram of operations during evacuation, and FIG. 3 is an explanatory diagram of operations during restoration. In the figure, 1... data file, 2... external storage device, 3... history file, 4... save file, 5... file system, 6... update means, 7...
. . . history output means, death . . . history search means, 9. . . saving means, 10. . . restoring means.

Claims (2)

[Claims] (1) A data file stored in an external storage device, an update unit that performs an update process on the data file, and a block I of the block that has been updated and updated by the update unit by updating the data file.
A history output means for outputting D to a history file; a history search means for obtaining a block ID stored in the history file at the time of evacuation; and an evacuation means for evacuation of a block having the block ID found by the history search means to an evacuation file. A file saving method characterized by comprising means. (2) A data file stored in an external storage device, an update unit that performs an update process on the data file, and a block I of a block that has been updated and updated by the update unit by updating the data file.
A history output means for outputting D to a history file; a history search means for obtaining a block ID stored in the history file at the time of evacuation; and an evacuation means for evacuation of a block having the block ID found by the history search means to an evacuation file. and a restoring means for restoring the data file based on the contents of the save file and the contents of the history file at the time of restoration.