JPH10333840A - Data recording and reproducing device and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make increasable the quantity of data, which are reproduced per unit time, by detecting the occurrence or non-occurrence of errors while reproducing the data on each prescribed unit, which are recorded by a 1st recording/reproducing means. SOLUTION: A disk array controller 15 reads separation data D13 out of the buffers 16A to 16E and also parity data D14 out of a buffer 16F and integrates the data D13 to reproduce the original coded data D22 and to send them to a reproduction control part 20. The part 20 decodes the data D22 and also applies a prescribed process to the data D22 to convert them into the original graphic data. At the same time, the status data D23 showing the reproducing result (occurrence of non-occurrence of errors) of the data D13 are added to the graphic data. Then, the acquired graphic data D24 are outputted to the outside via an interface circuit 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Table of Contents] The present invention will be described in the following order.

BACKGROUND OF THE INVENTION Prior Art (FIG. 7) Problems to be Solved by the Invention (FIGS. 8 and 9) Means for Solving the Problems (FIGS. 1 to 6) 1 to 6) Effects of the Invention

[0003]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording / reproducing apparatus and a data recording / reproducing method, and is suitably applied to, for example, a data recording / reproducing apparatus for recording / reproducing video data and a data recording / reproducing method.

[0004]

2. Description of the Related Art Conventionally, as a data recording / reproducing apparatus of this type, a plurality of hard disk drives are used as data recording / reproducing units in a RAID (Redundant Array of Inexpensive D).
There is a disk array device provided with a disk array device called an isks).

As shown in FIG. 7, in the disk array device 1, the level of RAID is defined according to the presence or absence of error correction and the degree of error correction. The data is separated into predetermined recording units such as sectors by the controller 2, and the separated data (hereinafter referred to as separated data) is simultaneously recorded and reproduced by the data recording and reproducing hard disk drives 3A to 3E. In both cases, the parity data is generated based on the separated data, and is recorded / reproduced on a dedicated hard disk drive 3F. RAID-3 (level 3)
There is a configuration called.

In the RAID-3 disk array device 1, a plurality of (for example, five) hard disk drives 3A to 3E (for example, five) are simultaneously driven for data recording / reproducing to record / reproduce the separated data. 3E has an advantage that it can be used as a data recording / reproducing unit having a transfer rate of about 5 times the execution transfer rate per unit and a recording capacity of 5 times the hard disk drives 3A to 3E. .

In this disk array device 1, parity data is recorded on a dedicated hard disk drive 3F, and even if one of the data recording / reproducing hard disk drives 3A to 3E fails, another normal operation is performed. Based on the separated data reproduced from the hard disk drives 3A to 3E and the parity data corresponding thereto, the failed hard disk drives 3A to 3E
Can be reconstructed.

In addition to this, in the disk array device 1, status data indicating whether or not the separated data has been correctly reproduced is added to the separated data reproduced by each of the hard disk drives 3A to 3E. Even when off-track occurs due to vibration or the like in any of the drives 3A to 3E or an error occurs in the separated data due to a defect caused by a flaw, etc., the correctly reproduced separated data detected based on the status data and Based on the corresponding parity data, the separated data in which an error has occurred can be reconstructed. In this way, the RAID-3 disk array device 1 can ensure relatively high reliability for data recording and reproduction, and has been widely used in recent years.

[0009]

In the data recording / reproducing apparatus having such a configuration, as shown in FIG. 8, when recording the separated data in each of the hard disk drives 3A to 3E in the disk array apparatus 1, a predetermined recording unit is required. Continuous separation data (A1, A2, A3, A4, A5, B1,
B2, B3...) Are cyclically distributed to the respective hard disk drives 3A to 3E, and the logical addresses (LBA: Logical Block Addrres) of the designated sectors of the respective hard disks are respectively allocated.
s) Record at location. At this time, the parity data (Ap, Bp, Cp, Dp,
... Are recorded in the dedicated hard disk drive 3F at the logical address positions of the designated sectors on the hard disk.

However, in the disk array device 1, any one of the hard disk drives 3A to 3
In the case where the separated data having an error (hereinafter referred to as error data) is recorded in E, the separated data is recorded in a logical address position subsequent to the logical address position where the error data is recorded in the hard disk drives 3A to 3E. Not stipulated.

For this reason, as shown in FIG. 9, in the disk array apparatus 1, as described above (FIG. 8), the separated data (F1, F2, F3) which is continuously connected to the hard disk drives 3A to 3E in which the separated data is once recorded. , F4, F5, G1, G2, G3
..) Are overwritten. At this time, for example, if error data is recorded in the hard disk drive 3C, new separated data (I3, J3) is placed after the logical address position where the error data is recorded in the hard disk drive 3C. ...) Are not recorded, but the old separated data (D3, E3...) Recorded earlier is recorded as it is.

Therefore, in the disk array device 1,
For example, a nonvolatile memory is provided, and information of all logical address positions after the logical address position where the error data of the hard disk drive 3C is recorded (information of the logical address position where new separated data is not recorded) is provided in the nonvolatile memory. ) Is stored to prevent old separated data recorded on the hard disk drive 3C from being read out based on the logical address position information stored and retained during data reproduction, and is originally recorded on the hard disk drive 3C. Data to be separated (I3, J3
...) Are reconstructed based on the separated data reproduced from the other hard disk drives 3A and 3B and 3D and 3E, and the parity data corresponding thereto.

However, in this case, in the disk array device 1, every time data reproduction is requested from the outside, the oldest one in each of the hard disk drives 3A to 3E is first determined based on the information on the logical address position stored and held in the nonvolatile memory. The logical address position where the separated data is recorded is searched, and when this search is completed, the data actually starts to be reproduced. As a result, in the data recording / reproducing apparatus provided with such a disk array device, the responsiveness to the data reproduction request is low, and the data amount of the video data that can be reproduced per unit time after the data reproduction is requested. There were few problems.

The present invention has been made in consideration of the above points, and has as its object to propose a data recording / reproducing apparatus and a data recording / reproducing method capable of increasing the amount of data reproduced per unit time.

[0015]

According to the present invention, there is provided a data recording / reproducing apparatus, comprising: a plurality of first recording / reproducing means; a second recording / reproducing means; A data distribution unit that adds first detection data for error detection for each unit and distributes the first detection data to each first recording / reproducing unit, and a first detection data distributed to each first recording / reproducing unit. Data generating means for generating first parity data for error detection based on the data and supplying the first parity data to the second recording / reproducing means; Recording control means for recording the first parity data in the second recording / reproducing means while recording the data for detection, and the data of each predetermined unit recorded in the first recording / reproducing means. First detection data Reproduction control means for reproducing the first parity data recorded on the second recording / reproducing means while reproducing the data, and the first detection data reproduced from each first recording / reproducing means. To generate the second parity data for error detection, and compare the generated second parity data with the first parity data reproduced from the second recording / reproducing means. An error detecting means for detecting the presence or absence of an error with respect to each predetermined unit of data reproduced from each first recording / reproducing means based on the comparison result is provided.

As a result, it is possible to detect whether or not an error has occurred with respect to the data in the predetermined unit while reproducing the data in the predetermined unit recorded in the first recording / reproducing means, thereby reproducing the data. Responsiveness to requests can be improved.

According to the present invention, in the data recording / reproducing method, the supplied data is added to the first detection data for error detection for each predetermined unit, and is distributed to a plurality of first recording media. Generating first parity data for error detection based on the respective first detection data distributed to the respective first recording media, applying the generated parity data to the second recording medium, The data of each predetermined unit and the first detection data are recorded on the medium, and the first parity data is recorded on the second recording medium.
And the first detection data recorded on the recording medium is reproduced from the second recording medium, and the first parity data recorded on the second recording medium is reproduced from the second recording medium. The second parity data for error detection is generated based on each of the first detection data thus generated, and the generated second parity data is compared with the reproduced first parity data. Then, based on the obtained comparison result, the presence or absence of an error in the reproduced data of each predetermined unit is detected.

As a result, it is possible to detect whether or not an error has occurred in the predetermined unit of data while reproducing the data of the predetermined unit recorded on the first recording medium from the first recording medium. Responsiveness to requests can be improved.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

In FIG. 1, reference numeral 10 denotes a data recording / reproducing apparatus as a whole, which is provided with a data recording / reproducing section 11 having a RAID-3 disk array configuration.

In this case, in the data recording / reproducing apparatus 10, at the time of data recording, video data D10 supplied for each predetermined unit from the outside is transferred to an interface circuit (I / F) 12
And the recording control unit 13 inputs it. The video data D10 input to the recording control unit 13
Is configured such that command data D11 composed of information on a logical address position of a sector indicating a recording area is added in advance to video data to be actually recorded.

The recording control unit 13 sequentially takes out the command data D11 from the inputted video data D10 for each predetermined unit, sends out the command data D11 to the system controller 14, and sequentially transmits the remaining actually recorded video data to the predetermined unit. After compression encoding by a compression encoding method and conversion into a predetermined recording format, the obtained encoded data D12 is sequentially transmitted to the disk array controller 15.

The disk array controller 15 encodes the encoded data D input from the recording control unit 13 in predetermined units.
12 and a plurality of separated data D13 of a predetermined recording unit are sequentially generated based on the plurality of hard disk drives 19A for data recording and reproduction.
The data is sent and written to a plurality of buffers 16A to 16E connected in parallel to the disk array controller 15 in a manner corresponding to .about.19E. In addition, the disk array controller 15 has a buffer 16
One parity data D14 of a predetermined recording unit is generated based on the five separated data D13 distributed from A to the buffer 16E, and is sent to the corresponding buffer 16F for writing.

At this time, the system controller 14 generates the recording control data D15 comprising information on the logical address position indicated by the command data D11,
(Small Computer System Interface) Protocol Controller (hereinafter referred to as SPC) 18A-18F
To send to.

As a result, each of the SPCs 18A to 18E has its own buffer 16A based on the recording control data D15.
16E, the read separated data D13 is sent to the corresponding data recording / reproducing hard disk drives 19A to 19E, and the read separated data D13 is sent to the logical address position of the sector of the hard disk represented by the recording control data D15. Record. Also SP
The C18F reads the corresponding parity data D14 from the buffer 16F based on the recording control data D15, sends the read parity data D14 to the dedicated hard disk drive 19F, and outputs the sector of the hard disk represented by the recording control data D15. At the logical address position.

In the data recording / reproducing apparatus 10,
At the time of data reproduction, reproduction request data D2 supplied from outside
0 is fetched through the interface circuit 12 and input to the system controller 14. The reproduction request data D20 input to the system controller 14
Is composed of information on a logical address position indicating a recording area of data requested to be reproduced.

The system controller 14 generates, based on the reproduction request data D20, reproduction control data D21 comprising information on the logical address position indicated by the reproduction request data D20,
C18A to 18F.

As a result, each of the SPCs 18A to 18E is connected to the corresponding hard disk drive 19A to 19E.
The separated data D13 recorded at the logical address position of the sector indicated by the recording control data D21 is read from the hard disk, and the read separated data D13 is sent to and written into the corresponding buffers 16A to 16E. Also, the SPC 18F stores the recording control data D2 from the hard disk of the corresponding hard disk drive 19F.
The parity data D14 recorded at the logical address position of the sector indicated by No. 1 is read, and the read parity data D14 is sent to the corresponding buffer 16F for writing.

Here, the disk array controller 15
Reads the separated data D13 from the buffers 16A to 16E, reads the parity data D14 from the buffer 16F, and integrates the separated data D13 while using the parity data D14 to obtain the original encoded data D22. Is reproduced, and the reproduction control unit 2
Send to 0. The disk array controller 15
Generates status data D23 indicating the reproduction result (whether or not an error has occurred) of the separated data D13 reproduced from the hard disks of the respective hard disk drives 19A to 19E, and sends this to the system controller 14.

The reproduction control section 20 converts the encoded data D22 into the original video data by decoding and performing predetermined processing on the encoded data D22. At this time, the status data D23 is input from the system controller 14 to the playback control unit 20. Accordingly, the playback control unit 20 adds the status data D2 to the video data.
3, and the obtained video data D24 is output to the outside via the interface circuit 12.

Here, in the disk array controller 15, a data distribution unit 25 operating at the time of data recording.
And a data integration unit that operates during data reproduction.

First, as shown in FIG. 2, in the data distribution unit 25 of the disk array controller 15, the encoded data D12 supplied from the recording control unit 13 is sequentially input to the delay buffer 26 and the selection circuit 27 in predetermined units. You.

The delay buffer 26 sequentially writes the input coded data D12 of each predetermined unit and sequentially changes the data arrangement for each of the written coded data D12 of the predetermined unit so that the number of data is smaller than at the time of writing. By reading out only a predetermined amount of data, first detection data D25 composed of all different random numbers is generated and sent to the selection circuit 27. The first detection data D25 generated in the delay buffer 26 is composed of the same number of second detection data as the number of hard disk drives 19A to 19E for data recording and reproduction (five in this case).

The data distribution unit 25 has a counter 28
The counter 28 repeatedly counts from 1 to a predetermined value at a predetermined timing, and sends counter data D26 representing the count value at that time to the selection circuit 27 at the counted timing.

Thus, the selection circuit 27 distributes the first detection data D25 at the timing when the counter data D26 representing the count value from 1 to 5 is input.
, And at a timing when the counter data D26 representing the count value from 6 to the predetermined value is input, the coded data D12 of the predetermined unit is transmitted to the distribution circuit 29. Thus, the selection circuit 27 outputs the first detection data D at the timing when the counter data D26 is input.
25 and the encoded data D12 are sequentially and alternately distributed to the distribution circuit 2
9

The distribution circuit 29 converts the first detection data D25 and the encoded data D12, which have been input alternately, into the end of the encoded data D12 and the first detection data D25.
Of the encoded data D1
Separation data D13 having a data amount of a predetermined recording unit obtained by adding the first detection data D25 to the header portion of No. 2
And the separated data D obtained by the generation
13 is sent out to each of the buffers 16A to 16E so as to be distributed cyclically. In addition, the distribution circuit 29 sends the separated data D13 to the corresponding first to fifth selectors 30A to 30E.

In this case, the first to fifth selectors 30A to 30A-3
0E is the counter data D2 from the counter 28, respectively.
6 as well as fixed value data D27 which is set in advance to a predetermined fixed value from the supply circuit 31 and has the same data amount as one second detection data.

In this state, the first to fifth selectors 3
In the case of 0A to 30E, first, when the counter data D26 representing the count value of 1 is input, the first selector 30A sets the first one of the first detection data D25 in the first detection data D25 in the separated data D13. The data is sent to the parity operation circuit 32 in place of the fixed value data D27, and the second to fifth selectors 30B to 30E detect the first one of the first detection data D25 in the separated data D13. The use data is sent to the parity operation circuit 32 as it is.

The first to fifth selectors 30A to 30E
When the counter data D26 representing the count value of 2 is input, the second selector 30B converts the second detection data from the head in the first detection data D25 into fixed value data D27. Instead, the data is sent to the parity operation circuit 32, and the first and third to fifth selectors 30A and 30C to 30E output the first detection data D25.
The second detection data from the top of the above is sent to the parity operation circuit 32 as it is.

Thus, the first to fifth selectors 30
In A to 30E, each time the counter data D26 representing the count value from 3 to 5 is input, the third, fourth, and fifth second detections from the top in the first detection data D25 are sequentially performed. Data is sent to the parity calculation circuit 32, and when the corresponding counter value set in advance is input, the second detection data of the same number as the count value from the top in the first detection data D25 Is transmitted to the parity operation circuit 32 in place of the fixed value data D27.

The third selector 30C is associated with a count value of 3, the fourth selector 30D is associated with a count value of 4, and the fifth selector 30E is associated with a count value of 5. . When the counter data D26 representing the count value from 6 to the predetermined value is input, the first to fifth selectors 30A to 30E change the encoded data D12 following the first detection data D25 in the separated data D13. It is sent to the parity operation circuit 32.

The parity operation circuit 32 outputs one fixed value data D27 from each of the first to fifth selectors 30A to 30E and the same second detection data from the head in each of the four first detection data D25. Each time data is input, one parity data for error detection (hereinafter, referred to as first detection parity data) is generated based on the total of five data, and thereafter, the first parity data is generated. -Fifth
, One parity data for reconstruction (hereinafter referred to as parity data for construction) is generated based on the five encoded data D12 input from the selectors 30A to 30E.

As described above, the parity operation circuit 32
One separate data D is provided for each of the buffers 16A to 16E.
Each time the data 13 is transmitted, the parity data D14 having a data amount of a predetermined recording unit is added by adding the generated five first parity data for detection to the header portion of the corresponding parity data for construction. Is generated, and the parity data D14 is sent to the buffer 16F.

As shown in FIG. 3, first hard disk drives 19A to 19E for recording and reproducing data are provided with first detection data D25 for recording first detection data D25 added to the header portion of the separated data D13.
And a second recording area for recording the encoded data D12 in the separated data D13.
In the same manner as described above, the first recording area for recording the five first parity data for detection added to the header portion of the parity data D14 is also provided on the hard disk of the hard disk drive 19F for recording the parity data D14. And a second recording area for recording construction parity data in the parity data D14.

On the other hand, as shown in FIG. 4, in the data integration unit 35 of the disk array controller 15, the separated data D1 read from each of the buffers 16A to 16E is read.
3 is input to the integration circuit 36 and input to the corresponding first to fifth selectors 37A to 37E.
The parity data D read from the buffer 16F
14 is input to the integration circuit 36 and the comparison circuit 3
8 is input.

Here, the first to fifth selectors 37A to 37A
E indicates that counter data D30 identical to counter data D26 is repeatedly input from counter 39 having the same configuration as counter 28 of data distribution unit 25 described above,
The fixed value data D31 that is the same as the fixed value data D27 is input from the supply circuit 40 having the same configuration as the supply circuit 31 of the data distribution unit 25 described above.

In this state, the first to fifth selectors 3
7A to 37E, when the counter data D30 representing the count value of 1 is input, the first selector 37A sets the first one of the first detection data D25 in the first detection data D25 in the separated data D13. The data is sent to the parity operation circuit 41 in place of the fixed value data D31, and the second to fifth selectors 37B to 37E detect the first second detection signal in the first detection data D25 in the separated data D13. The use data is sent to the parity operation circuit 41 as it is.

The first to fifth selectors 37A to 37E
When the counter data D30 representing the count value of 2 is input, the second selector 37B converts the second detection data from the head in the first detection data D25 into fixed value data D31. Instead, the data is sent to the parity calculation circuit 41, and the first and third to fifth selectors 37A and 37C to 30E output the first detection data D25.
The second detection data from the head of the second is sent to the parity operation circuit 41 as it is.

In this way, the first to fifth selectors 37
In A to 37E, every time the counter data D30 representing the count value from 3 to 5 is input, the third, fourth, and fifth second detection signals from the head in the first detection data D25 are sequentially output. Is transmitted to the parity operation circuit 41, and when a corresponding counter value set in advance is input, the second data of the same number as the count value from the head in the first second detection data D25 is output. The detection data is sent to the parity operation circuit 41 instead of the fixed value data D31.

The third selector 37C is associated with a count value of 3, the fourth selector 37D is associated with a count value of 4, and the fifth selector 37E is associated with a count value of 5. . When the counter data D26 representing the count value from 1 to the predetermined value is again input to the first to fifth selectors 37A to 37E, the same operation as described above is performed and the fixed value data 31 and the new The second detection data in the first detection data D25 is sent to the parity operation circuit 41.

The parity operation circuit 41 outputs one fixed value data D31 from each of the first to fifth selectors 37A to 37E and the same second detection data from the head in each of the four first detection data D25. Each time the input data is input, one second parity data for detection D32 is generated based on the total of five data, and these are sequentially transmitted to the comparison circuit. At this time, the counter data D30 is input from the counter 39 to the comparison circuit 38.

Each time the counter data D30 representing the count value from 1 to 5 is input, the comparison circuit 38 sequentially counts from the head of the five first detection parity data in the parity data D14. The first parity data for detection having the same number as the value is extracted, and the second parity data D32 for detection corresponding to the extracted first parity data for detection is output to the parity calculation circuit 4.
Input from 1. Thus, the comparison circuit 38 extracts 1 from the parity data D14 every time the counter data D30 representing the count value from 1 to 5 is sequentially input.
The first parity data for detection and the corresponding parity data D32 for second detection are compared, and the comparison result is sent to the integration circuit 36 as comparison result data D33.
When the comparison results do not match, the comparison circuit 38 outputs the comparison result data D33, for example, which is an error flag, to the integration circuit 3.
Send to 6.

Based on the comparison result data D33 input from the comparison circuit 38, the integration circuit 36
The presence / absence of an error is detected for the encoded data D12 in the separated data D13 input from A to 16E. In this case, in the integration circuit 36, each encoded data D1
When no error has occurred for the data No. 2, these are integrated to reproduce the original coded data D22. Further, when an error occurs in the encoded data D12 (even when the old encoded data D12 is reproduced), the encoded data D12 in the other separated data D13 corresponding to the encoded data D12 and Based on the parity data for construction of the corresponding parity data D14, the coded data D12 in which an error has occurred is reconstructed and integrated, and thus the original coded data D22 is reproduced. The integration circuit 36 sends the obtained encoded data D22 to the reproduction control unit 20 in this manner.

In the data distribution section 25, when the parity calculation circuit 32 generates the first detection parity data, the five second parity data in the first detection data D25 are used.
The detection data of H (m, n) (m = 0, 1,...,
4, n = 0, 1,..., 4) (where m represents the position of the data from the head in the first detection data D25, and n represents the hard disk drive 19A on which the data is to be recorded). represents a ~19E), it represents the fixed value data D27 and FF (hex), the first detection parity data _{P H (q) (q =} 0,1, ......, 4) as (q Part 1 represents the order in which the parity data for detection is generated).

[0055]

(Equation 1)

Can be generated as represented by In this case, in the parity calculation circuit 32, the second detection data to be recorded on the hard disk drives 19A to 19E are sequentially replaced with the fixed value data D27 to generate each first detection parity data. .

When generating parity data for construction, the parity operation circuit 32 converts the encoded data D12 into D
(R, n) (r indicates the order of generation), and the parity data for construction is expressed as P _D (r) by a function of Parity, and the following equation (2) is obtained.

[0058]

(Equation 2)

Can be generated as represented by In this way, the parity operation circuit 32 calculates the equation (1)
And the parity data D14 of the formula (2) is sent to the buffer 16F and the corresponding hard disk drive 19 is sent.
F can be recorded.

As shown in FIG. 5, the separation data D13 and the parity data D14 are correctly recorded on each of the hard disk drives 19A to 19F.
It is assumed that the separated data D13 and the parity data D14 are correctly reproduced from the respective hard disk drives 19A to 19F.

In this case, in the data integration section 35, the parity calculation circuit 41 stores the first detection data D25 reproduced from each of the hard disk drives 19A to 19E in the same manner as the parity calculation circuit 32 of the data distribution section 25 described above. Of the second detection data of H ′ (m, n)
And each second parity data for detection D32 is represented by P
Expressing each as a function of Parity as _C (q), the following equation (3)

[0062]

(Equation 3)

Can be generated as represented by In this case as well, in the parity operation circuit 41, the second detection data to be recorded on the hard disk drives 19A to 19E are sequentially replaced with fixed value data D31 to generate each second detection parity data D32. ing.

As described above, the parity operation circuits 32 and 41
In the first and second parity data for detection D32 generated respectively in (1) and (2), since the separation data D13 is generated by substantially the same equations (1) and (3), the separated data D13 is generated as described above. When the corresponding ones are sequentially compared with each other from the beginning in the comparison circuit 38 in a state where the data is correctly reproduced, the following equation (4) is obtained.

[0065]

(Equation 4)

As can be seen from the above, it is possible to obtain comparison results that match all. As a result, the integration circuit 36 determines each of the separated data D13 based on the comparison result data D33.
Is correctly detected.

By the way, as shown in FIG. 6, for example, consider a case where the erroneous separated data D13 is recorded in one of the hard disk drives 19A to 19F.

In this case, in the data integration section 35, the parity operation circuit 41 uses the hard disk drive 19A
-19E, the five second detection data in the error-detected first detection data D25 are represented by X ′
(M, n) and each second detection parity data D3
2 is expressed as a function of Parity as P _E (q).
The following equation (5)

[0069]

(Equation 5)

Is generated as shown in FIG.

Here, each of the second detection parity data D32 generated by the parity calculation circuit 41 is compared with the corresponding first detection parity data generated by the parity calculation circuit 32, respectively. The following equation (6)

[0072]

(Equation 6)

As shown in the above, the first detection data corresponding to only one second detection data in the first detection data D25 reproduced from the hard disk drive 19B is replaced by the fixed value data D31. The second parity data D3 that matches the parity data for detection,
2 does not match the corresponding first detection parity data.

That is, the data distribution unit 35 can detect which of the hard disk drives 19A to 19E caused the error in the separated data D12 based on the comparison result indicating the mismatch based on the comparison result data D33, and can also perform the comparison indicating the match. According to the result, the hard disk drives 19A to 19E in which an error has occurred in the separated data D13 can be specified.

In this case, the data distribution unit 35 generates new separated data D13 not only when an error occurs in the hard disk drives 19A to 19E but also due to the occurrence of an error in the hard disk drives 19A to 19E.
When the old separated data D13 is recorded as it is without being recorded, it can be detected in the same manner as described above.

In the data recording / reproducing apparatus 10 having the above-described configuration, at the time of data recording, the data distribution section 25 adds the first detection data D2 to the encoded data D12.
5 and sequentially generate the separated data D13,
The obtained plurality of separated data D13 is cyclically distributed to the respective hard disk drives 19A to 19E to be recorded on the hard disk.

The data distribution unit 25 extracts the second detection data corresponding to the four different hard disk drives 19A to 19E sequentially from the first detection data D25 allocated to the respective hard disk drives 19A to 19E. At the same time, the first data is sequentially obtained based on the four extracted second detection data and the fixed value data D27.
Is generated and recorded on the hard disk of the hard disk drive 19F together with the construction parity data as parity data D14.

On the other hand, in the data recording / reproducing apparatus 10,
At the time of data reproduction, each hard disk drive 19A-19
Separate data D13 recorded on the hard disk of E is reproduced from the hard disk, and parity data D14 recorded on the hard disk of the hard disk drive 19F is reproduced and input to the data integration unit 35.

The data integration unit 35 extracts the second detection data corresponding to the four different hard disk drives 19A to 19E sequentially from the first detection data D25 reproduced from the respective hard disk drives 19A to 19E. The second parity data for detection D32 is sequentially generated based on the four extracted second detection data and the fixed value data D31. In addition, the data integration unit 35 sequentially compares each of the generated second detection parity data D32 with the corresponding first detection parity data in the reproduced parity data D14, and The separated data D reproduced based on the comparison result
13 to determine whether or not an error has occurred in the encoded data D12.

As described above, in the data recording / reproducing apparatus 10,
While reproducing the separated data D13 and the parity data D14 respectively recorded from the respective hard disk drives 19A to 19F, it is possible to detect whether or not an error has occurred in the reproduced separated data D13. Responsiveness to the actual execution of the reproducing operation in response to the data reproducing request can be improved as compared with the reproducing apparatus.

In the data recording / reproducing apparatus 10, when the first and second detection parity data D32 are generated, one of the five second detection data sequentially differs from the other.
By using the fixed value data D27 and D31 instead of the two second detection data, an error occurs when the corresponding first and second detection parity data D32 are compared with each other. The hard disk drives 19A to 19E on which the generated separated data D13 has been reproduced can be easily detected.

Further, in the data recording / reproducing apparatus 10,
By making the second detection data all different values,
Even when the old second detection data is generated at the time of data reproduction from the logical address position where the old second detection data is not recorded without being overwritten at the time of data recording,
This can be reliably detected as erroneous data.

According to the above configuration, the first detection data D25 is sequentially added to the coded data D12 in the predetermined unit to generate a plurality of separated data D13, and the plurality of separated data obtained by the generation is generated. D13 is distributed to and recorded on each of the hard disk drives 19A to 19E, and the corresponding second detection data sequentially extracted from the first detection data D25 distributed to each of the hard disk drives 19A to 19E, and a fixed value. The first parity data for detection is generated on the basis of the data D27 and recorded on the hard disk drive 19F. Thereafter, the separated data D13 and the first detection data recorded on the hard disk drive 19A to 19F are recorded from the respective hard disk drives 19A to 19F. The parity data is reproduced, and the separated data D13 in the first detection data D25 of each of the reproduced data D13 are read. The second detection parity data D32 is generated based on the corresponding second detection data sequentially extracted and the fixed value data D31, and the generated second detection parity data D32 and Comparing the reproduced first parity data for detection,
Based on the comparison result, the separated data D13 reproduced
Of the encoded data D12 in the hard disk drive 19A to 19F, the separated data D12 recorded on the hard disk drives 19A to 19F are detected.
13 and the parity data D14, the presence / absence of an error in the separated data D13 can be detected, thereby making it possible to detect the occurrence of an error from the request of data reproduction to the actual execution of the reproduction operation, as compared with the related art. Responsiveness can be improved, and a data recording / reproducing apparatus capable of increasing the amount of data reproduced per unit time can be realized.

In the above-described embodiment, a case has been described in which video data is compressed and encoded by the recording control unit 13. However, the present invention is not limited to this. May be converted to a recording format and sent to the disk array controller 15. In this case, the same effect as in the above-described embodiment can be obtained.

In the above-described embodiment, the case has been described where the first detection data D25 is added to the header portion of the coded data D12 by the data distribution unit 25. However, the first detection data D25 may be added to the foot portion of the encoded data D12 by the data distribution unit 25.

Further, in the above-described embodiment, the case has been described where the first detection data D25, which is a random number generated from the encoded data D12, is added to the encoded data D12. The present invention is not limited to this, as long as different values of data can be added to each of the encoded data D12 having a predetermined data amount, and various other data are added to the encoded data D12 as first detection data. You may do it.

Further, in the above embodiment, the data recording / reproducing unit 11 of the data recording / reproducing device 10
Although the description has been made of the case where the disk array device having the configuration of -3 is applied, the present invention is not limited to this, and a data recording / reproducing unit having various other configurations may be applied.

Furthermore, in the above-described embodiment, a case has been described where video data is recorded and reproduced by the data recording / reproducing apparatus 10. However, the present invention is not limited to this, and various other data such as audio data may be used. May be recorded and reproduced.

Further, in the above-described embodiment, the first
And the case where the second parity data for detection D32 is generated based on one fixed value data D27 and D31 and the four second detection data D25 has been described. However, the first and second parity data for detection may be generated based on four detection data D25 corresponding to four different hard disk drives 19A to 19E. Also in this case, the coded data D12 in which an error has occurred can be easily specified as in the above-described embodiment.

Further, in the above-described embodiment, a case has been described in which the hard disk drives 19A to 19E are applied as the plurality of first recording / reproducing means. However, the present invention is not limited to this, and the present invention is not limited to this. As described above, various other first recording / reproducing means may be applied.

Further, in the above embodiment, the second
Hard disk drive 19F
Has been described, but the present invention is not limited to this, and various other second recording / reproducing means such as a memory may be applied.

Further, in the above-described embodiment, the supplied data D12 is supplied to the first recording / reproducing means 19A together with the first detection data D25 for error detection in predetermined units.
To the data distribution unit 25, the delay buffer 26 of the data distribution unit 25, the selection circuit 2
7, the case where the counter 28 and the distribution circuit 29 are applied has been described. However, the present invention is not limited to this, and the supplied data D12 is used together with the first detection data D25 for error detection for each predetermined unit. Each first recording / reproducing means 19A
~ 19E, various other data distribution means may be applied.

Further, in the above-described embodiment, first parity data for error detection is generated based on each first detection data D25 distributed to each of the first recording / reproducing means 10A to 19E. The counter 28 of the data distribution unit 25 includes the first parity data thus generated to the second recording and reproducing unit 19F.
The case where the fifth selectors 30A to 30E, the supply circuit 31, and the parity operation circuit 32 are applied has been described. However, the present invention is not limited to this, and is divided among the first recording / reproducing means 10A to 19E. If first parity data for error detection is generated based on each of the first detection data D25 and can be provided to the second recording / reproducing means 19F, various other data generating means are applied. You may do it.

Further, in the above-described embodiment, each of the first recording / reproducing units 19A to 19E is provided with the data distribution unit 2A.
The data D12 and the first detection data D25 of each predetermined unit given from 6, 27, 28 and 29 are recorded, and the data generation means 28, 30A to 30E, 31 and 32 are stored in the second recording / reproducing means 19F. Recording control means for recording the first parity data provided from
Although the case where the system controller 14, the buffers 16A to 16F and the SPCs 18A to 18F are applied has been described, the present invention is not limited to this, and the data distribution means 26, 27, 2
The data D12 of each predetermined unit and each first detection data D25 given from the data recording means 8 and 29 are recorded, and the data generating means 28 and 30A are transmitted to the second recording / reproducing means 19F.
As long as the first parity data provided from .about.30E, 31 and 32 can be recorded, various other recording control means may be applied.

Further, in the above-described embodiment, the data D12 and the first detection data D25 of each predetermined unit recorded from each of the first recording / reproducing means 19A to 19E are reproduced, and the second recording is performed. As the playback control means for playing back the first parity data recorded from the playback means 19F, the system controller 14 and the buffers 16A to 16A are used.
16F and SPCs 18A to 18F have been described, but the present invention is not limited to this.
The data D12 and the first detection data D25 of each predetermined unit recorded from the recording / reproducing means 19A to 19E are reproduced, and the first parity data recorded from the second recording / reproducing means 19F is reproduced. If possible, various other reproduction control means may be applied.

Further, in the above-described embodiment, each of the first recording / reproducing means 19A to 19E reproduced by
The second parity data D32 for error detection is generated based on the detection data D25, and the generated second parity data D32 and the second recording / reproducing means 19 are generated.
F and the first parity data reproduced from the first parity data, and based on the obtained comparison result, each first recording / reproducing means 19A
As error detecting means for detecting whether or not an error has occurred in each predetermined unit of data D12 reproduced from -19E.
Although the case where the data integration unit 35 is applied has been described, the present invention is not limited to this, and each first detection data D reproduced from each of the first recording / reproducing means 19A to 19E.
25, the second parity data D3 for error detection based on
2 is generated, the generated second parity data D32 is compared with the first parity data reproduced from the second recording / reproducing means 19F, and each first parity data is reproduced based on the obtained comparison result. If it is possible to detect the presence or absence of an error in each predetermined unit of data D12 reproduced from the recording / reproducing means 19A to 19E, various other error detecting means may be applied.

[0097]

As described above, according to the present invention, a plurality of first recording / reproducing means, a plurality of second recording / reproducing means, and a first detecting means for detecting an error in the supplied data for each predetermined unit. Data distribution means for adding the data for use to the first recording / reproducing means and providing the data to the first recording / reproducing means, and the first data for error detection based on the first detection data allocated to the first recording / reproducing means.
Data generating means for generating parity data of the first and second types, and providing the same to the second recording and reproducing means; and recording each predetermined unit of data and each first detection data in each of the first recording and reproducing means. Recording control means for recording the first parity data in the second recording / reproducing means, and reproducing and reproducing each predetermined unit of data and each first detection data recorded in the first recording / reproducing means from the respective first recording / reproducing means. A reproduction control means for reproducing the first parity data recorded in the second recording / reproducing means from the second recording / reproducing means, and an error detection based on each first detection data reproduced from each of the first recording / reproducing means. And generating the second parity data for use with the second parity data, and comparing the generated second parity data with the first parity data reproduced from the second recording / reproducing means. Each first note based on An error detecting means for detecting whether or not an error has occurred with respect to each predetermined unit of data reproduced from the reproducing means is provided, so that each predetermined unit of data recorded in the first recording / reproducing means is recorded. The presence or absence of an error in the data of the predetermined unit can be detected during the reproduction, whereby the responsiveness to the data reproduction request can be improved, thus increasing the amount of data reproduced per unit time. The obtained data recording / reproducing apparatus can be realized.

Further, the supplied data is distributed to a plurality of first recording media by adding first detection data for error detection to each of the predetermined recording units, and is distributed to each of the first recording media. First parity data for error detection is generated based on each first detection data, and the first parity data is supplied to a second recording medium, and data of each predetermined unit and each first data are stored in each first recording medium. And the first parity data is recorded on the second recording medium. Thereafter, the data of each predetermined unit recorded on the first recording medium and the first detection data are recorded on the second recording medium. Data for the second
The first parity data recorded on the recording medium is reproduced from the recording medium, and the second parity data for error detection is generated based on the reproduced first detection data. The reproduced second parity data is compared with the reproduced first parity data, and based on the obtained comparison result, whether or not an error has occurred in the reproduced data of each predetermined unit is detected. By doing, the first
It is possible to detect the occurrence of an error in the data of the predetermined unit while reproducing the data of the predetermined unit recorded on the recording medium from the recording medium, thereby improving the responsiveness to the data reproduction request. Thus, it is possible to realize a data recording / reproducing method capable of increasing the amount of data reproduced per unit time.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a data recording / reproducing apparatus according to the present invention.

FIG. 2 is a block diagram showing a configuration of a data distribution unit of the disk array controller.

FIG. 3 is a schematic diagram showing a recording format of a hard disk in a hard disk drive for recording and reproducing data.

FIG. 4 is a block diagram showing a configuration of a data integration unit of the disk array controller.

FIG. 5 is a schematic diagram showing a state in which data is correctly recorded on each hard disk drive.

FIG. 6 is a schematic diagram illustrating a state in which data in which an error has occurred is recorded on a hard disk drive.

FIG. 7 is a block diagram showing a configuration of a general disk array device.

FIG. 8 is a schematic diagram showing a state where data is correctly recorded on each hard disk drive.

FIG. 9 is a schematic diagram illustrating a state where data having an error is recorded on a hard disk drive.

[Explanation of symbols]

10 data recording / reproducing device, 11 data recording / reproducing section, 15 disk array controller, 16A-1
6F ... Buffer, 18A-18F ... SPC, 19A
-19F: Hard disk drive, 25: Data distribution unit, 26: Day buffer, 27: Selection circuit, 28, 39 ... Counter, 29: Distribution circuit, 30
A, 37A ... first selector, 30B, 37B ... second selector, 30C, 37C ... third selector, 3
0D, 37D: fourth selector, 30E, 37E ...
Fifth selector, 31, 40... Supply circuit, 32, 41
... Parity operation circuit, 35 Data integration unit, 36
... Integrated circuit, 38 ... Comparison circuit.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G11B 20/18 572 G11B 20/18 572F

Claims (6)

[Claims] A plurality of first recording / reproducing means, a plurality of second recording / reproducing means, and a method for adding supplied first detection data for error detection to the supplied data for each predetermined unit. Data distributing means distributed to the recording / reproducing means, and the first data distributed to the first recording / reproducing means.
Data generating means for generating first parity data for error detection based on the data for detection of the above, and providing the generated first parity data to the second recording / reproducing means; The recording / reproducing means records each of the predetermined unit data and each of the first detection data provided from the data distribution means, and the first recording / reproducing means provides the first data provided from the data generating means to the second recording / reproducing means. Recording control means for recording parity data; and reproducing the data of each of the predetermined units and each of the first detection data recorded from each of the first recording and reproducing means, and the second recording and reproducing means. Playback control means for playing back the first parity data recorded from the first and second recording means, and an error detection means for error detection based on each of the first detection data reproduced from each of the first recording and playback means. The second parity data is generated, and the generated second parity data is compared with the first parity data reproduced from the second recording / reproducing means. A data recording / reproducing apparatus comprising: an error detecting means for detecting whether an error has occurred in each of the predetermined units of data reproduced from each of the first recording / reproducing means. 2. The method according to claim 1, wherein the first detection data comprises the same number of second detection data as the number of the first recording / reproducing means. The second detection data corresponding to each of the recording / reproducing means is extracted from the first detection data allocated to the means by one less than the different number sequentially from the first detection data, and one more than the extracted number. The first parity data is generated based on a small number of each of the second detection data and fixed value data set in advance to a predetermined fixed value, and the error detection means includes a first parity data generating unit that generates the first parity data. From the first detection data reproduced from the recording / reproducing means, the number of the second detection data corresponding to each of the recording / reproducing means, which is one less than the different number sequentially, is extracted. One less than Each said second detection data,
2. The data recording / reproducing apparatus according to claim 1, wherein the second parity data is generated based on fixed value data set to a predetermined fixed value in advance. 3. The apparatus according to claim 1, wherein the data distribution means distributes the first detection data different for each of the predetermined units of data to each of the first recording / reproducing means. Data recording and playback device. 4. A first step in which supplied data is added to first detection data for error detection for each predetermined unit and distributed to a plurality of first recording media, and each of the first steps is provided. First parity data for error detection is generated based on each of the first detection data allocated to the recording medium, and the generated first parity data is stored in a second parity data.
A second step to be applied to the first recording medium; and recording the data of the predetermined unit and the first detection data on each of the first recording media.
A third step of recording the first parity data on the first recording medium, reproducing the predetermined unit data and the first detection data recorded from the first recording medium, and A fourth step of reproducing the first parity data recorded from the second recording medium, and an error based on each of the first detection data reproduced from each of the first recording media. A second parity data for detection is generated, and the generated second parity data is compared with the first parity data reproduced from the second recording medium. And a fifth step of detecting whether an error has occurred in each of the predetermined units of data reproduced from each of the first recording media based on the result. 5. The first detection data is composed of the same number of pieces of second detection data as the number of the recording media. In the second step, the first detection data is distributed to each of the first recording media. The second detection data corresponding to each of the recording media, which is one less than the number that is sequentially different from the first detection data, is extracted from each of the first detection data, and each of the first detection data is one less than the extracted number. The first parity data is generated based on the second detection data and fixed value data set in advance to a predetermined fixed value. In the fifth step, each of the first recording / reproducing means is used. The second detection data corresponding to each of the recording / reproducing means is extracted from the first detection data reproduced from the first detection data, the number being sequentially smaller by one than the above number, and one less than the retrieved number. The number of each second 5. The data recording / reproducing method according to claim 4, wherein the second parity data is generated based on the detection data and the fixed value data set to a predetermined fixed value in advance. 6. The method according to claim 4, wherein in the first step, the first detection data different for each of the predetermined units of data is distributed to each of the first recording media and given. Data recording and playback method.