JPH0728674A - Erased file restoring method - Google Patents

Abstract

PURPOSE:To easily restore a file without storing file management information by an operator. CONSTITUTION:This is a method for restoring an erased file on a file device having a file recording area wherein plural files 6 and 7 are recorded and a file management area 2 wherein pieces 3 and 4 of management information corresponding to the files are recorded; when a specified file 6 is erased, the management information 3 on the specified erased file in the file management area 2 is copied to an auxiliary file management area 9 and then part or the whole of the management information 3 is erased. When the file 6 is already erased is restored, the management information 3 copied to the auxiliary file management area 9 is written back to the file management area 2 to restore the erased file.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file restoration method in a file device which is a storage device such as an electronic computer, and more particularly to an erased file restoration method capable of easily restoring a file once erased from a file device.

[0002]

2. Description of the Related Art Generally, a floppy disk device or a magnetic disk device used as an external recording device of an electronic computer records / records a file of data or a program.
It is configured to be reproducible and erasable, and management information including a file name / recording position, attributes, etc. is recorded in a file management area (FAT) corresponding to a file. To delete a file in this file device, by deleting a part or all of the management information of the deleted file in the file management area by the file deletion command, it is as if the contents of the file were deleted from the outside. In general, the file contents are deleted until the contents of the deleted file are overwritten with other file contents.

As a method for preventing the erroneous erasure of the file, in the prior art, for example, JP-A-62-17104 is used.
As described in Japanese Patent Publication No. 9, even if the file deletion is instructed by the operator, the file device holds the deletion of the file for the corresponding deleted file for a certain period of time so that the operator can delete the file within a certain period of time. There has been proposed a method of canceling the file erasing instruction when the erroneous erasing of is noticed.

In addition, in a file device which erases a part of the management information of the file, for example, a part of the file name, to artificially delete the file from the outside,
A file recovery method has also been proposed in which a part of the management information erased by the operator is manually recovered to recover the management information and thereby recover the file.

[0005]

In the file erroneous erasure prevention method according to the above-mentioned conventional technique, the file device executes the erasure of the corresponding file after the lapse of the above-mentioned certain time. However, if you notice that the file was accidentally deleted, there was a problem that you could not restore the necessary file.

Further, the file restoration method described later has a problem that the management information cannot be restored unless the operator stores some or all of the management information of the deleted file. In particular, when restoring a large number of files, there is also a problem that the recovery work is complicated because the management information of all the deleted files must be stored.

An object of the present invention is to eliminate the above-mentioned problems caused by the conventional technique, and to provide a file restoration method by which an operator can easily restore a file without storing the file management information. is there.

[0008]

In order to achieve the above object, the present invention is directed to erasing a file device having a file recording area for recording a plurality of files and a file management area for recording management information corresponding to the plurality of files. In the file restoration method, when deleting a specified file, copy the management information of the specified deleted file in the file management area to another area and then delete part or all of the management information of the specified deleted file. When restoring the erase file, the first feature is to restore the erase file by writing back the management information copied in the other area to the file management area.

Further, according to the present invention, in a method of restoring an erased file having a file recording area and a file management area, when erasing a designated file, the management information of the designated erased file in the file management area is When a new file is recorded by deleting a part or all of the management information of the specified deletion file in the file management area after copying to the area, the recording empty area of the file device is insufficient for the new file capacity. In this case, it is confirmed whether or not a new file is overwritten on the erased file in the file recording area, and when restoring the erased file that has not been overwritten, the management information copied to the other area is managed. The second feature is that the erased file is restored by writing back to the area.

[0010]

In the file restoration method according to the first feature, when erasing a designated file, the management information of the designated erasure file is saved in another area and then part or all of the management information is erased. The erased file can be restored by writing back the management information saved in the other area to the file management area.

In the file restoration method according to the second feature, when erasing a designated file, the management information of the designated erasure file is saved in another area and then part or all of the management information is erased. When recording a new file, if the recording free area of the file device is insufficient for the new file capacity, check whether or not the erased file in the file recording area is overwritten with a new file. Thus, the erased file that has not been overwritten can be restored by writing back the management information saved in the other area to the file management area.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A file restoration method according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing states before and after file deletion of a file device that realizes the recovery method according to this embodiment. Left and right file devices 1 shown in the figure
A and 1B are the same, but different reference numerals 1A and 1B are added to distinguish before and after file erasing. The file device 1A shown on the left side of FIG. 1 shows an initial state of a file. , The files 6 and 7 which are data are recorded, and the files 6 and 7 are recorded.
File name / attribute for (Read-Only, Hidden, Archi
ON / OFF of ve, update date, etc.) / Recording position (cluster) /
This shows that management information 3 and 4 including sizes and the like are recorded in the file management area 2. The file device 1 according to the present embodiment is provided with an auxiliary file management area 9 for recording a copy of the file management area 2 in addition to the recording area.

When erasing, for example, the file 6 from the file device 1A, the present file restoration method is such that the management information 3 and 4 in the file management area 2 is copied to the auxiliary file management area 9 and then the deleted file 6 is deleted. File management area 2 by deleting part or all of management information 3
To update. This state is shown in the file device 1B, which apparently erases part or all of the management information 3'in the file management area 2, so that the file 6 is deleted from the outside. However, the file 6 which is the actual data remains stored internally.

When the file 6 erased from the state of the file device 1B is restored, the restoration method according to this embodiment uses the management information 3 and 4 recorded in the auxiliary file management area 9 before the file deletion. The file is restored by writing back to area 2. That is,
In the file device 1B, since the file 6 itself, which is the data content, is not erased, the auxiliary file management area 9 is used to write back the file management area 2 to restore the state of the file device 1A.

As described above, the file restoration method according to the present embodiment can extremely easily restore the file by writing back the file management information before the file is erased. Although not shown, the restored file device stores the same management information in the file management area 2 and the auxiliary file management area 9, and when a new file is erased, the file management area 2 is rewritten as described above. The file may be erased after re-copying the contents of the above into the auxiliary file management area 9, or the file may be deleted without rewriting the auxiliary file management area 9 because of the same contents.

Next, a file restoration method according to the second embodiment of the present invention will be described with reference to FIG. 2 by distinguishing the file devices from the reference numerals 1C, 1D and 1E in this figure as well. The file device 1C in the initial state according to the present embodiment records files 6, 7, and 8 which are data, and also has a file name / attribute (Re
ad-Only, Hidden, Archive ON / OFF, update date, etc.) /
Management information 3 consisting of recording position (cluster) / size etc.
5 is recorded in the file management area 2, and an erase file management area 10 is provided for copying and storing only management information of an erase file, which will be described later.

When the file 6 is first erased from the file device 1C, the present file restoration method is such that after copying only the management information 3 corresponding to the erased file 6 in the file management area 2 to the erased file management area 10, The file management area 2 is updated by erasing a part or all of the management information 3 of the deleted file 6. This state is shown in the file device 1D. Since this device 1D apparently erases part or all of the management information 3'in the file management area 2, the file 6 is deleted from the outside. The file 6 which is the actual data is stored internally.

Next, when further erasing the file 7 from this file device 1D, this method copies only the management information 4 corresponding to the erasing file 7 in the file managing area 2 to the erasing file managing area 10, A part or all of the management information 4 of the deleted file 7 is deleted and the file management area 2 is updated again. This state is shown in the file device 1E. When the file management area 2 is referred to from the outside, the file device 1E looks like the existing file in the file device is only the file 8, but the file 6 to All 8 data are stored.

When recovering the deleted files 6 and 7 from the state of the file device 1E, the recovery method according to the present embodiment uses the management information of the deleted files 6 and 7 recorded in the deleted file management area 10. 4 and 5
Is restored to the file management area 2 to restore the file. That is, in the file restoration method according to the present embodiment, the management information of the erased file is stored in the erased file management area 10 when the file is erased. File management information in file management area 2
The file is restored by writing it back to. The management information to be written back from the erased file management area 10 to the file management area 2 can be arbitrarily selected by the operator, so that the file to be restored can be easily selected.

In the file restoration method according to this embodiment, only the management information of the erased file is saved and restored, so that even if the file is erased by mistake several times, the erased file can be restored. In addition, any erased file can be selectively restored.

Next, a file restoration method according to the third embodiment of the present invention will be described with reference to FIG. 3 by distinguishing the file devices from the reference numerals 1F, 1G and 1H also in this figure. The file device 1F in the initial state in this embodiment has the erased file management area 10 as in the second embodiment, and the file 6 is erased, that is, part or all of the management information 3 of the file 6 is deleted. A method of adding a new file 8 to the file device 1F will be described.

First, in the file device 1F, when there is an empty area in which a file is newly recorded, this file restoration method uses the file 8 which is new data in the empty area of the file device like the file device 1G shown in the lower left of the figure.
Is written, the management information corresponding to the file 8 is written in the file management area 2, and processing is performed so that the data in the file 6 is not erased. As described above, when the file device has an empty area, a new file is recorded in the empty area. Therefore, in the present embodiment, when the file 6 is restored, the erased file management area 10 is used as in the second embodiment.
It is possible to recover by writing back the management information 3 corresponding to the file 6 to the file management area 2.

If there is a shortage of free areas when a new file 8 is newly recorded from the state of the file device 1F (including the case where the capacity of the file 8 is larger than the free area capacity), the present file restoration method is the same as above. When a new file 8 is overwritten in the recording area of the apparently erased file 6, the operator is asked whether or not the file 8 can be overwritten in the recording area of the file 6, and the permission of overwriting is confirmed. After that, the file 8 is overwritten and the management information 3 corresponding to the file 6 in the deleted file management area 10 is also deleted at the same time. In this way, when there is no free area in the file device, it is necessary to confirm with the operator the actual deletion of the apparently deleted file contents.
It is possible to prevent the actual erasure of the required file (content), and then to restore the file as described above. If the operator denies the erasure of the file contents in the confirmation of the erasure of the file contents, once the erased file is restored by the above method and moved to another file device, a new file may be written. good.

As described above, in the file restoration method according to the present embodiment, when a new file is recorded after the file has been erased once, if there is an empty area in the file device, a new file is recorded in the empty area, and the empty area is recorded. If there is no such file, it is possible to prevent erroneous irreversible erasure of a file required for erasing after confirming the actual erasing operation of the file (content).

[0025]

As described above, in the file restoration method according to the present invention, when the designated file is erased, the management information of the designated erased file is copied to another area, for example, the auxiliary file management area or the erased file management area. Later, when a part or all of the management information is erased and the erased file is restored, the erased file can be restored by writing back the management information saved in the other area to the file management area.

Further, in the file restoration method according to the present invention, when erasing a designated file, the management information of the designated erasure file is saved in another area and then part or all of the management information is erased. If the recording free area of the file device is insufficient for the new file capacity when recording a new file, by confirming whether or not the erased file in the file recording area is overwritten with a new file, The erased file that has not been overwritten can be restored by writing back the management information saved in the other area to the file management area.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a file restoration method according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a file restoration method according to a second embodiment of the present invention.

FIG. 3 is a diagram for explaining a file restoration method according to a third embodiment of the present invention.

[Explanation of symbols]

1A to 1H ... file device, 2 ... file management area,
3 ... management information of file 6; 4 ... management information of file 7; 5 ... management information of file 8; 6 ... (data) file, 7 ... (data) file, 8 ... (data) file, 9 ... auxiliary file management Areas 9, 10 ... Erase file management area.

Claims (2)

[Claims] 1. A method for recovering an erased file in a file device, comprising: a file recording area for recording a plurality of files; and a file management area for recording management information corresponding to the plurality of files, wherein a specified file is erased. When
When the management information of the specified erased file in the file management area is copied to another area, a part or all of the management information of the specified erased file in the file management area is erased and the erased file is restored. Is a method for restoring an erased file, wherein the erased file is restored by writing back the management information copied to the other area to the file management area. 2. A method for recovering an erase file of a file device, comprising: a file recording area for recording a plurality of files; and a file management area for recording management information corresponding to the plurality of files, wherein a specified file is erased. In this case, the management information of the specified erased file in the file management area is copied to another area, and then part or all of the management information of the specified erased file in the file management area is erased to create a new file. When the recording free area of the file device is insufficient for the new file capacity at the time of recording, it is confirmed whether or not the erased file in the file recording area is overwritten with a new file, and the overwriting is not performed. When recovering the erased file, erase the management information copied to the other area by writing it back to the file management area. A method for recovering deleted files, characterized by recovering files.