JPH0619767A - Magnetic disk device with file restoration function - Google Patents

Abstract

PURPOSE:To restore a destroyed file as against power cut while data is outputted to the file. CONSTITUTION:A magnetic disk controller with file restoration function 1 is provided with an output control means 2 outputting data to a magnetic disk 7, an output data storage means 3 which stores output data from a host device 9 and which can hold data when power is cut, an output control information storage means 4 which can hold the information on an output position and output data length, which are noticed from the host device 9 and which the output control means 2 records even if power is cut, and an output state storage means 5 which can hold the recording of the state of an output processing which the output control means 2 records even if power is cut and a file restoration means 6 which checks the output state storage means 5 at the time of re-raising and requests re-output to the output control means 2 when power cut during output is recognized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device with a file recovery function, and more particularly to a magnetic disk device with a recovery function capable of recovering a file on a disk which is destroyed by a power supply while outputting data to the magnetic disk device.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, a magnetic disk control device of this type has an output control means 2a which is notified of an output position and an output data length from a host device 9 and output data from the host device 9. Is stored in the output data storage means 3a
Composed of and.

The host device 9 is a file 8 on the magnetic disk 7.
In order to output the data, the output data is notified to the output data notifying means, and the output control means 2a is notified of the output position and the data length of the output data as an output request.

The output control means 2a of the magnetic disk control device 1a is used to specify the data stored in the output data storage means 3a to the output position specified by the host device 9 by the specified data length and to be the output target disk. Output to file 8 of 7.

[0005]

In the above-mentioned conventional magnetic disk control device, if a power failure or a momentary interruption occurs during data output to the file 8, the file 8 may be destroyed.

The output position and output data length notified from the host device 9 and the data in the output data storage means 3a are not guaranteed due to the power failure, so that the write process cannot be re-executed and the recovery is difficult. There was a point.

[0007]

A magnetic disk controller with a file recovery function according to the present invention includes an output control means for outputting data to a magnetic disk and output data stored from a host device even when the power is cut off. An output data storage unit capable of holding the output data, an output control information storage unit capable of storing the output position and the output data length notified by the above-mentioned output control unit from the host device, and storing the information even when the power is cut off, The output control means records the output processing state, and the output state recording means that can hold the record even when the power is cut off, and the output state of the output state storage means at the time of restarting, and recognizes the power cut during output. In this case, the output control means has a file recovery means for requesting re-output.

[0008]

Embodiments of the present invention will now be described in detail and specifically with reference to the drawings.

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

The magnetic disk control device 1 with a file recovery function stores output data from the output control means 2 for outputting data to the magnetic disk 7 and the host device 9 and can hold the data even when the power is cut off. Storage means 3
Then, the output control means 2 records the output position and the output data length notified from the higher-level device 9, and the output control information storage means 4 capable of holding the information even when the power supply is cut off, and the output control means 2 of the output processing. The output state storage means 5 which records the state and can retain the record even when the power is cut off, and the output state storage means 5 at the time of restarting are checked, and when the power cutoff during output is recognized, the output control means 2 is notified. The file recovery means 6 makes a re-output request.

FIG. 2 is a flow chart showing an embodiment of the present invention. Next, the operation of the present invention will be described with reference to FIG.

According to the diagram (A) of FIG. 2, since the host device 9 outputs the data to the file 8 of the magnetic disk, the output data is notified to the output data storage means 3 (step 101), Further, the higher-level device 9 notifies the output control means 2 of the output position and the output data length of the output data as an output request (step 102).

Upon receiving the request, the output control means 2 stores the information of the output position of the output data and the output data length in the output control information storage means 4 (step 103), and "outputting data" in the output state storage means 5. Is notified (step 104), and the data is stored in the output data storage means 3 at the output position designated by the host device 9 by the data length designated by the data, and is output to the file 8 of the disk 7 having the output symmetry. Execute (step 105).

When the output is finished, the output control means 2 notifies the output state storage means of the state of "data output completed" (step 106), and the control device 1 finishes the output processing.

Next, according to the diagram (B) of FIG. 2, the file restoration means 6 checks the state of the output state storage means 5 when the control device 1 is restarted, and is in the "data output" state. At the time (step 201), the output control means 2 is requested to output the data again (step 202).

Upon receiving the request, the output control means 2 acquires the output position and the output data length from the output control information storage means 4 (step 203) and uses the data stored in the output data storage means 3. File 8 on disk 7
Output processing is executed to (step 204).

Similar to the above-mentioned processing, at the end of the output processing, "data output completed" is output to the output means 2 output state storage means 5.
Is notified (step 205), and the control device 1
Finish the startup of.

During data writing process (step 105)
And 204), there is no need to restore the file because the contents of the file remain the same as before or after the normal writing.

[0019]

As described above, the present invention is provided with the output data storage means for storing the output data from the host device and capable of retaining the data even when the power is cut off. Even if the power is cut off, the damaged part can be restored when restarting.

[Brief description of drawings]

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

FIG. 2 is a flowchart illustrating the operation of the embodiment of the present invention.

FIG. 3 shows an example of the configuration of a conventional magnetic disk control device.

[Explanation of symbols]

 1 Magnetic disk controller with file recovery function 1a Magnetic disk controller. 2, 2a Output control means 3, 3a Output data storage means 4 Output control information storage means 5 Output state storage means 6 File recovery means 7 Magnetic disk 8 File 9 Upper device

Claims (1)

[Claims] 1. An output control means for outputting magnetic disk data, an output data storage means for storing output data from a host device and holding the data even when the power is cut off, and the output control means for notifying from the host device. The output control information storage means for recording the output position and the output data length, and capable of holding the information even when the power is cut off, and the output processing information recording means for recording the status of the output processing, and the record can be held even when the power is cut off. Output state storage means and file restoration means for checking the output state of the output state storage means at the time of restarting and requesting re-output to the output control means when the power-off during output is recognized Magnetic disk controller with file recovery function.