JP2002055863A - Data restoring method and system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data restoring method and its system to restore the deficit of data due to not only a failure of hardware but also a failure to be generated on a system such as an OS, application or human error. SOLUTION: To a data writing instruction from a host computer 101, a controller 102 transfers the leading block address, data length and record data to a data input/output means 103, transfers the leading block address, the data length, the record data and recording time to a change recording means 104, the data input/output means 103 records the record data at a position of the block address to be specified by the leading block address and the data length of a first recording means 106 and the change recording means 104 records the leading block address, the data length, the record data and the recording time in a change recording list recorded and created on a second recording medium 107.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data restoring method and system for restoring data recorded in a recording means, and more particularly, to a failure of hardware or software related to a recording means for recording data or a human error. The present invention relates to a data restoration method and system for restoring data loss or an error caused by a factor including an error.

[0002]

2. Description of the Related Art A conventional data restoration method of this kind is described, for example, in "Paul Massiglia, The RAID Book 6thedition, Peer t
o Peer Communications, San Jose, 1997 ". In the conventional data restoration method described in this document, a plurality of recording media are used, and when recording data, the same data is recorded on the plurality of recording media, or parity data generated by calculation from the data to be recorded is calculated. By making the recording data redundant by recording, etc., even if data from a certain recording unit of one recording medium is lost among a plurality of recording media, the data recorded on another recording medium is The data is protected by restoring the missing data.

[0003]

In the above-described conventional data restoration method, data restoration can be performed in response to a hardware defect such as a physical defect on a recording medium or a head for reading a signal. For example, there is a problem that data cannot be restored with respect to writing of incorrect data generated due to a failure of the OS or application of the host computer, or writing of incorrect data due to a user's misunderstanding or the like. .

[0004] The present invention has been made in view of the above,
It is an object of the present invention to provide a data restoration method and system for restoring not only hardware failure but also data loss due to a failure such as an OS or an application on a system or a human error.

[0005]

According to a first aspect of the present invention, there is provided a data restoration method for restoring data recorded in a recording means, wherein the data to be recorded is recorded in the recording means. Each time data is recorded in the recording means on the basis of the number of recording unit areas in which data is recorded and the start address thereof, the recording data, the number of recording unit areas, the start address, and the recording time that have been recorded are recorded in another record. Means for recording, and when it is necessary to restore the data recorded in the recording means due to factors including hardware and software failures, the additional information based on the information including the head address and the number of the recording unit area or the recording time. The gist is to read data from the recording means and restore the data.

According to the first aspect of the present invention, each time data is recorded on the recording means based on the number of recording unit areas in which data is recorded and the head address thereof, the number of recording data and the number of recording unit areas are changed. If it is necessary to record the start address and recording time in another recording means and to restore the data due to factors including hardware and software failures, the information including the start address and number of the recording unit area or the recording time Data is read from another recording means and restored based on the data. Therefore, not only data restoration due to hardware data reading errors such as a physical defect of the recording means and a head for reading a signal, but also the OS and application of the host computer. Wrong data writing due to failure or wrong data writing by user Restore data against also can be carried out in suitable probability.

According to a second aspect of the present invention, there is provided a data restoration system for restoring data recorded in a recording means, wherein the data to be recorded is determined by the number of recording unit areas in which the recording data is recorded, and A recording control means for controlling the recording data, the number of recording unit areas, the start address, and the recording time to be recorded in another recording means every time recording is performed in the recording means based on the start address. When it is necessary to restore the data recorded in the recording unit due to a factor including a failure of hardware and software, from the another recording unit based on the information including the head address and the number of the recording unit area or the recording time. It is essential to have a data restoring means for reading and restoring data.

According to the second aspect of the present invention, each time data is recorded in the recording means based on the number of recording unit areas in which data is recorded and the start address thereof, the number of recording data and the number of recording unit areas are changed. If it is necessary to record the start address and recording time in another recording means and to restore the data due to factors including hardware and software failures, the information including the start address and number of the recording unit area or the recording time Data is read from another recording means and restored based on the data. Therefore, not only data restoration due to hardware data reading errors such as a physical defect of the recording means and a head for reading a signal, but also the OS and application of the host computer. Wrong data writing due to failure or wrong data writing by user Restore data against also can be carried out in suitable probability.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a data restoration system that performs a data restoration method according to an embodiment of the present invention. The data restoration system shown in FIG. 1 has a first recording medium 106 constituting recording means for recording data used by the host computer 101 and the like, and a method in which data recorded on the first recording medium 106 is lost. There is a second recording medium 107 which constitutes another recording means for recording the data each time the data is recorded on the first recording medium so that the data can be restored.

The host computer 101 is connected to the controller 102, further connected from the controller 102 to the first recording medium 106 via the data input / output means 103, and from the controller 102 to the change recording means 104 or the data restoring means. Second via 105
Is connected to the recording medium 107.

Next, the operation of the data restoration system configured as described above will be described with reference to the flowcharts shown in FIGS.

First, an operation at the time of data writing will be described with reference to FIG.

In the data write operation, the host computer 101 transfers a data write command to the controller 102 (step S11). Upon receiving the data write command from the host computer 101, the controller 102 transfers a data request packet to the host computer 101 (Step S13). Upon receiving the data request packet, the host computer 101 transfers the data to be recorded to the controller 102 (Step S15).

When the controller 102 receives data from the host computer 101, the data input / output means 1
03, a data write command, a head block address which is a number indicating a recording location on the first recording medium 106 for writing data, a data length, and data to be recorded are transferred (step S17). The head block address, the data length, the recording data, and the recording time are transferred to 104 (step S2).
1).

The data input / output means 103 includes a data write command from the controller 102 to the data input / output means 103, a head block address which is a number indicating a recording location on the first recording medium 106 for writing data, a data length, When the recording data is received, the recording data is recorded at the position of the block address specified by the head block address and the data length (step S19).

When the change recording means 104 receives the head block address, data length, recording data, and recording time from the controller 102, the change recording means 104 stores the head block address, data length, recording data, and recording time in the second recording area. The data is recorded in a change record table as shown in FIG. 8, which is recorded and created on the medium 107, so that when data is read from the first recording medium 106, for example, data due to hardware or software failure or human error, etc. It is prepared for data restoration when data cannot be read from the first recording medium 106 due to data loss or the like (step S23).

The change recording means 104 may record the difference between the record data in a change record table as shown in FIG. 9, for example, instead of recording the record data in a change record table as shown in FIG. Things. That is, the change record table shown in FIG. 9 records the head block address, the data length, the difference between the record data, and the record time under the control of the change record unit 104. Also, the record numbers of the change record tables shown in FIGS. 8 and 9 may be explicitly written in the tables, or may be substituted by the block addresses of the recording media for recording the tables. In addition, this change record table is, for example, Ziv
-It may be compressed by a universal lossless code such as Lempel code.

Next, the operation at the time of data reading will be described with reference to the flowchart shown in FIG.

In the data read operation, the host computer 101 transfers a data read command, a head block address of data to be read, and a data length to the controller 102 (step S31). When receiving the data read command, the first block address, and the data length, the controller 102 transfers the data read command, the first block address, and the data length to the data input / output unit 103 (step S3).
3). When the data input / output means 103 receives the data read command and the block address, the first recording medium 1
Data is read out from step 06 (step S3).
5).

Next, the data input / output means 103 determines whether or not the data reading was successful (step S).
37) If the data has been successfully read, the read data is transferred to the controller 102 (step S39). When receiving data from the data input / output means 103, the controller 102 transfers the data to the host computer 101 (step S4).
1).

However, when the data input / output means 103 fails to read data from the first recording medium 106, the data input / output means 103 reads the data which could be read from the first recording medium 106. The data is transferred to the controller 102, and the head block address and the data length of the failed read are reported to the controller 102 (step S43). In this case, if there are a plurality of failures, the failed start block address and data length are reported to the controller 102.

Upon receiving the report from the data input / output means 103, the controller 102 transfers the data read command, the reported head block address, and the data length to the data restoring means 105 (step S45). The data restoring means 105 acquires from the second recording medium 107 the data corresponding to the head block address and the data length recorded in the record of the latest change data from the change record table shown in FIG. 8 or FIG. The data is transferred to the controller 102 (step S47).

In this case, when using a change record table in which record data as shown in FIG. 3 is recorded as it is as a change record table, for example, when reading of data having a head block address 1 and a data length 1 fails. Figure 8
"A" is acquired from the change record table of "1" and transmitted. Further, for example, when the reading of the data having the head block address 5 and the data length 3 has failed, “468” is acquired from the change record table of FIG. 8 and transmitted.

When a change record table that records the difference of the record data as shown in FIG. 9 is used as the change record table, for example, when reading of the data of the head block address 5 and the data length 2 fails, Using the change record table shown in FIG. 9, the data having a data length of 2 is added at the first block address 5 from the oldest recording time to the newest recording time, and 2 + 2 = 4 is calculated for the block address 5. For the block address 6, "46" is obtained from the calculation of 3 + 3 = 6, and this data "46" is transmitted from the data restoration means 105 to the controller 102. Here, for the sake of simplicity of description, they are treated as numbers, but actually, addition or the like is performed in byte units or sector units.

The controller 102 has a data restoration unit 1
05 is merged with the data obtained from the data input / output means 103 and transferred to the host computer 101 (step S49).

Next, referring to the flowchart shown in FIG. 7, an operation for restoring the writing of erroneous data generated due to a failure of the OS or application of the host computer 101 or the writing of erroneous data due to user misunderstanding or the like. Will be described.

When it is detected by the data matching software on the host computer 101 or that humanly wrong data has been written (step S61), the data matching software or the human host computer 10
From step 1, the data restoration command and the recording time of the data to be restored are transferred to the controller 102 (step S63). The controller 102 transmits the change recording read command and the recording time to the data restoring unit 105 (step S6).
5).

The data restoring means 105 transmits a record of a change record from the last write time or the first write time (that is, the latest recording time or the time at which recording was started) to the recording time to be restored to the controller 102 ( Step S67).

The controller 102 is a data restoration unit 1
When the record of the change record is received from the data input / output unit 103, the data write command, the top block address, the data length, and the data are received based on the change record.
(Step S69). Data input / output means 10
3 receives the data write command, the head block address, the data length, and the data from the controller 102, and records the data at the position of the block address specified by the head block address and the data length (step S71).

Further, the controller 102 also sends a head block address, a data length,
The recording data and the recording time are transmitted (step S7).
3). The change recording unit 104 records the start block address, the data length, the recording data, and the recording time received from the controller 102 by attaching a record number to the change recording table shown in FIG. 8 (step S75). in this case,
The above-mentioned recording may be compressed and recorded by a universal reversible code such as a Ziv-Lempel code. In this case, the controller 102 transfers the data so that the data is rewritten sequentially from the latest one, and performs data rewriting at a desired recording time.

FIG. 2 is a block diagram showing a configuration of a data restoration system for implementing a data restoration method according to another embodiment of the present invention. The data restoration system shown in FIG.
While the embodiment shown in FIG. 1 uses two recording media, that is, a first recording medium 106 and a second recording medium 107, a single recording medium 206 obtained by integrating these two recording media is used. This embodiment is different from the embodiment shown in FIG. 1 only in that it is configured to record both data on this one recording medium.

FIG. 3 is a block diagram showing a configuration of a data restoration system for implementing a data restoration method according to another embodiment of the present invention. The data restoration system shown in FIG.
While the embodiment shown in FIG. 1 uses the same type of recording medium as the first recording medium 106 and the second recording medium 107, different types of recording media 306 and 307 are used.
, And the other configurations and operations are the same as those of the embodiment shown in FIG. 1.

FIG. 4 is a block diagram showing the configuration of a time-designated voice notification system for implementing a data restoration method according to still another embodiment of the present invention. The data restoration system shown in the figure differs from the embodiment shown in FIG. 2 in that an autochanger-type data storage device 406 is used as the recording medium 206, and other configurations and operations are the same as those shown in FIG. Same as the form.

When the recording medium to be written by the change recording means 104 is separate from the recording medium to which the recording data is to be written, as in the data restoration system shown in FIGS. The medium is Wr
It is preferable that the recording medium is a large-capacity recording medium of the item Once type.

When the recording medium to be written by the change recording means 104 is integrated with the recording medium to which the recording data is written as in the data restoration system shown in FIGS. 2 and 4, the change recording means 104 It is preferable that the writing area is not rewritable. For example, the data input / output unit 103, the change recording unit 104,
When the data restoring unit 105 operates as a separate process on one host, the change record table has a write right to the change record table only in a process that implements the change recording unit 104, and the change record unit 104 This can be realized by writing the change record table in the addition mode during the process of (1).

[0036]

As described above, according to the present invention,
Each time data is recorded in the recording means based on the number of recording unit areas in which data is recorded and its start address, the recording data, the number of recording unit areas, the start address, and the recording time are recorded in another recording means. When it is necessary to restore data due to factors including hardware and software failures, data is read from another recording means and restored based on information including the start address and number of the recording unit area or the recording time. Not only data restoration due to hardware data read error such as physical defect of means or head reading signal, but also incorrect data writing due to failure of host computer OS or application or wrong due to user misunderstanding etc. Data restoration for data writing can be performed accurately. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a data restoration system that implements a data restoration method according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a data restoration system that implements a data restoration method according to another embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration of a data restoration system that performs a data restoration method according to another embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a data restoration system that implements a data restoration method according to still another embodiment of the present invention.

FIG. 5 is a flowchart showing an operation at the time of data writing of the data restoration system of the embodiment shown in FIGS. 1 to 4;

FIG. 6 is a flowchart showing an operation at the time of data reading of the data restoration system of the embodiment shown in FIGS.

FIG. 7 is a flowchart showing the operation of the data restoration system of the embodiment shown in FIGS. 1 to 4 when restoring erroneous data writing;

8 is a diagram showing a change record table when recording data used in the data restoration system of the embodiment shown in FIGS. 1 to 4 is recorded as it is.

FIG. 9 is a diagram showing a change record table when a difference between record data used in the data restoration system of the embodiment shown in FIGS. 1 to 4 is recorded.

[Explanation of symbols]

 Reference Signs List 101 host computer 102 controller 103 data input / output unit 104 change recording unit 105 data restoration unit 106, 306 first recording medium 107, 307 second recording medium 206 recording medium 406 autochanger type data storage device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Tetsuya Ura 2-3-1 Otemachi, Chiyoda-ku, Tokyo Inside Nippon Telegraph and Telephone Corporation (72) Katsuhiro Endo 2-3-3 Otemachi, Chiyoda-ku, Tokyo No. 1 F-term in Nippon Telegraph and Telephone Corporation (reference) 5B082 DC02 EA01 5D044 AB01 BC01 CC05 DE38 DE39 DE49 DE83 EF05 FG18 GK19 HL06

Claims (2)

[Claims] 1. A data restoration method for restoring data recorded in a recording means, wherein data to be recorded is stored in the recording means based on the number of recording unit areas in which the recording data is recorded and its head address. Each time recording is performed, the recording data, the number of recording unit areas, the start address, and the recording time at which this recording was performed are recorded in another recording means, and are recorded in the recording means due to factors including hardware and software failures. A method for restoring read-out data from the other recording means based on information including the start address and the number of recording unit areas or the recording time when it is necessary to restore the recorded data. 2. A data restoration system for restoring data recorded in a recording means, wherein data to be recorded is stored in the recording means based on the number of recording unit areas in which the recording data is recorded and the head address thereof. Each time recording is performed, recording control means for controlling the recording data, the number of recording unit areas, the start address, and the recording time at which the recording is performed to be recorded on another recording means, and a failure of hardware and software. Data restoration means for reading and restoring data from the other recording means based on information including the start address and the number of recording unit areas or the recording time when it is necessary to restore the data recorded in the recording means due to factors including A data restoration system comprising: