JP2005302111A - Information recording method to a plurality of information recording media and information reproducing method from the plurality of information recording media - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information recording control method for recording random data at high speed by using a plurality of information recording media in parallel. <P>SOLUTION: Recording information is sequentially recorded on the recording media as a packet of an address and data. At the same time, the recording information is managed on a cache by constructing an address translation table (shows the newest actually recorded locations). Since all pieces of recording instruction information on time series are recorded on the plurality of recording media, there is no risk such as tampering and high reliability is realized, and moreover, since sequential recording is performed physically in the recording media, there is no overhead of access and an actual recording speed can be increased. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a parallel information recording / reproducing system for recording information on a plurality of information recording media via a plurality of information recording / reproducing means.

As an example of the information recording system, an example of a conventional optical recording system will be described with reference to FIGS.
FIG. 4 shows a block diagram of a conventional optical recording / reproducing apparatus. Light emitted from a laser light source 25 (wavelength of about 660 nm in DVD-RAM) that is a part of the head 2 is collimated into a substantially parallel light beam 22 through a collimator lens 24. The light beam 22 is irradiated onto the optical disk 11 through the objective lens 23 to form a spot 21, and then guided to the servo detector 26 and the signal detector 27 through the beam splitter 28 and the hologram element 29.

  Signals from each detector are added and subtracted to become servo signals such as tracking error signals and focus error signals, and are input to the servo circuit. The servo circuit controls the position of the driving means 31 of the objective lens 23 and the entire optical head 2 based on the obtained tracking error signal and focus error signal, and positions the position of the light spot 21 in the target recording / reproducing area. The addition signal of the detector 27 is input to the signal reproduction block 41. The input signal is digitized after being filtered and frequency equalized by a signal processing circuit.

  The digitized digital signal is processed by an address detection circuit and a demodulation circuit. The microprocessor calculates the position of the light spot 21 on the optical disk 11 based on the address signal detected by the address detection circuit, and controls the automatic position control means to set the optical head 2 and the light spot 21 to the target recording unit. Position to an area (sector).

  When the instruction from the host apparatus to the optical recording / reproducing apparatus is recording, the microprocessor receives recording data from the host apparatus and stores it in the memory, and controls the automatic position control means to control the light spot 21 for the target recording. Position to the area position. The microprocessor confirms that the light spot 21 is normally positioned in the recording area based on the address signal from the signal reproduction block 41, and then controls the laser driver or the like to record the data in the memory in the target recording area. .

  As shown in FIG. 6, since the address signal is arranged for each information recording unit area and is arranged at the head of the recording unit area, the position of the light spot is detected immediately before recording by detecting the address signal. Can be confirmed.

  As another arrangement method of address signals, a widely used method is a method of recording address information by displacement of an information recording track, that is, wobble, as shown in FIG. In any case, data is arranged and recorded according to address information arranged in advance on the disc.

  As a method for increasing the recording speed of information in such an optical recording system, for example, as described in Reference 1 (Technical Digest of Optical Data Storage 2003, TuA71), the disk is rotated at a high speed and the recording speed can be increased. By improving the recording characteristics of the medium itself and performing high-speed recording, or by transferring multiple disks in parallel as described in Reference 2 (Japanese Journal of Applied Physics Vol.39, pp 920-924) A speed-up method is described.

On the other hand, a method of recording data sequentially on a recording medium while realizing random data recording to suppress the number of accesses is, for example, a method using a UDF VAT (Virtual Allocation Table) adopted in CD-R. Yes, this method is described in detail in Universal Disk Format Specification (Revision 1.50) (Non-patent Document 3) published by Optical Storage Technology Association (http://www.osta.org). In this method, the data itself is always recorded sequentially on a write-once medium or the like, and only the management information part of the data is arranged in the virtual address area for 512 sectors, and the data for 512 sectors is actually written to where. This is realized by recording an address table (VAT) indicating whether or not it has been recorded on the disk immediately before the medium is taken out.
As a method for suppressing the number of accesses while recording data on a plurality of recording media, there is a method described in JP-A-7-38854.

JP-A-7-38854

Technical Digest of Optical Data Storage 2003, TuA71 Japanese. Journal of Applied Physics Vol.39, pp 920-924 Universal Disk Format Specification (Revision 1.50) published by Optical Storage Technology Association (http://www.osta.org)

  However, in any example of Non-Patent Documents 1 and 2, although the recording speed can be improved, if the size of the data to be recorded is small, as shown in FIG. Will drop significantly. FIG. 5 shows the measurement of the effective transfer rate of an optical disc recording system that performs recording on an optical disc apparatus (DVD-RAM) using four types of file system drivers (A, B, C, and D). Thus, the problem that the effective transfer rate decreases when the size of the file to be recorded is small is that the access speed to the optical disk is relatively low, about several tens of ms to 100 ms, and the file size is small. The main factor is considered to be the dominant access overhead.

  Such an overhead problem due to access cannot be simply solved even in the case of the method using a plurality of optical disks described in Document 2. In other words, by distributing the recording data to a plurality of optical disks, the effective file length recorded on each optical disk becomes smaller and, as a result, the effect of recording in parallel on a plurality of optical disk drives is lost. It will be broken.

  In the method of Non-Patent Document 3, the virtual address area for recording management information is limited to 512 sectors, and if the system ends abnormally before the address table (VAT) is recorded, Recorded information could be lost. Also, a method for dealing with a plurality of disks is not disclosed.

  The method of Patent Document 1 is arranged so that information from a plurality of disks can be read synchronously while distributing and accumulating stream data having a long recording data length such as video information to ensure a high transfer rate. The number of times of access is suppressed by the above, and a method for dealing with general random data other than video is not disclosed.

  An object of the present invention is to provide an information recording control method capable of recording random data at high speed using a plurality of information recording media in parallel. It is another object of the present invention to provide a high-reliability and high-speed high-speed recording / reproducing system in which the record information change history remains reliably and there is no risk of data loss even when the system is shut down.

In order to achieve the object of the present invention, the following means were used.
(1) An information recording / reproducing method for recording or reproducing information on a plurality of information recording media via a plurality of information recording / reproducing means,
When recording information on the plurality of information recording media,
Selecting one of the plurality of information recording media;
At least a step of recording information using a combination of address information for identifying recording data and recording data at a recording position immediately after a position where information is recorded immediately before in the information recording area of the selected information recording medium To record.

  This makes it possible to record information in parallel on a plurality of recording media, thus enabling high-speed and large-capacity recording. In addition, since recording is always performed from the position immediately after the position where the information was recorded immediately before the recording medium, the recording on the selected recording medium is always sequential and the data is continuous. Does not occur. In addition, since address information and data are always recorded together, the recorded content is compensated even if the system goes down in the middle. In addition, since only sequential recording is performed, random recording can be performed effectively using a write-once recording medium.

(2) An address conversion table indicating the relationship between the address information and recording positions on the plurality of media is recorded on the recording medium.
As a result, the position information of the actually recorded information can be known without scanning on the recording medium during reproduction, so that the performance during reproduction is improved.

(3) The address conversion table is recorded in the temporary storage means in the recording apparatus and then transferred to the recording medium.
As a result, even when it becomes necessary to update the address conversion table by additionally writing, the time required for changing the address conversion table can be shortened, so that the high-speed recording performance is further improved.

(4) The address conversion table was recorded on a plurality of recording media as events.
As a result, even if some of the plurality of address conversion tables become unreadable due to some cause, the address conversion table can be reliably reproduced and reliability is improved.

(5) The selection of one of the plurality of information media is performed so as to average the busyness of the plurality of information recording / reproducing means.
As a result, recording can be performed while avoiding a busy recording / reproducing apparatus, so that the performance of the entire system is improved.
The method of averaging the busyness in the first half is to average the amount of data sent to the drive that drives each recording medium, as well as to detect the amount of data stored in the cache in the drive (temporary memory) via the interface, There are methods such as selecting a drive with the least amount of data in the cache.

(6) An information recording / reproducing method for recording or reproducing information on a plurality of information recording media via a plurality of information recording / reproducing means,
When recording information on the plurality of information recording media,
Selecting one of the plurality of information recording media;
In the information recording area of the selected information recording medium, address information for identifying the recording data, recording data, and a sequence number indicating the recording order of the recording data are recorded at the recording position immediately after the position where the information was recorded immediately before. It was decided to carry out the steps of recording information as a set.

  With this sequence number, it is possible to obtain time-series information about which information was written first among the information that is distributed and recorded on multiple media. It is possible to discriminate the finally recorded data and restore the recorded state at an arbitrary point in the past. This restoration function of the recording state at an arbitrary time improves the reliability of backup and the like.

(7) constructing an address conversion table from information recorded on a plurality of information recording media and storing it in a temporary storage means;
Identifying a recording position on a plurality of recording media of recording information of a target address using an address conversion table on the temporary storage means;
The recorded information is reproduced by at least a step of reading the information of the identified recording position from the corresponding information recording medium.
By having this address conversion table on the temporary storage means, address conversion can be realized substantially in real time. Therefore, the target information can be accessed immediately when data is reproduced.

(8) Reading and verifying the address conversion table recorded on the plurality of information recording media in the step of constructing an address conversion table from the information recorded on the plurality of information recording media and storing it in the temporary storage means; When the validity of the address conversion table is confirmed as a result of the verification, the address conversion table is stored in the temporary storage means,
As a result of the verification, when it is not possible to confirm that a valid address conversion table exists on a plurality of recording media, the address conversion is performed on the temporary storage means based on the address information and the order information recorded on the plurality of recording media. We decided to rebuild the table.

  As a result, when the address conversion table is normally recorded, it can be immediately reproduced as any address information, and when the address conversion table is not normally recorded, Time for reconstruction work is required, but since all recorded information is recorded in pairs with addresses, information is not lost, and it is possible to achieve both high speed and high reliability.

  (9) As the address information for identifying the recording information, the recording block information instructed from the host or the higher-level information processing means or the converted one is used. Thereby, the target address information of the recording command from the host always remains on the recording medium, so that address conversion can be easily realized.

According to the present invention, since all the records (commands) performed in time series are “recorded”, all record histories remain, so there is no fear of falsification and the like, and high reliability. Also, since it is physically sequential recording, there is no access overhead and the effective recording speed is improved.
The effects of the present invention are not limited to the above embodiments. For example, although DVD-R is taken up as an optical disk, this is a technique applicable to all recording media including write-once type and rewritable type.

  The present invention will be described in detail using the following examples.

  FIG. 2 shows the configuration of a parallel transfer system that transfers data in parallel to a plurality of optical disks. In the example of FIG. 2, four optical recording drives are each connected to the parallel transfer controller 51 via an interface. The parallel controller itself is a host interface that receives commands from the host side and sends data when requested by the host side, and a drive interface that sends and receives data and commands to each drive. Processing such as conversion, division, and combination can be performed.

Next, when comparing the file system of the present invention developed for this synchronous system with the conventional file system, the following problems of the conventional file system construction are as follows:
(1) A file management method with low overhead.
(2) Streamlined recording information update method independent of file size.
(3) Ensuring high reliability.
Met.

  It is desirable to record data as sequentially as possible by reducing the overhead access. For example, in the example of the UDF file system shown in FIG. 5A, the recording performance is ensured by caching data and reducing the number of management information updates. However, from the viewpoint of reliability, all files are recorded after recording. A system that updates file information is considered less desirable. Therefore, the method shown in FIG. 1 was devised as a method of solving the seemingly contradictory problem of reducing access and ensuring reliability.

  In this method, for all recording commands, a target address (LBA) and data are paired and sequentially recorded at actual locations on a plurality of disks. When dividing the recording data into multiple discs, it is possible to select whether or not to divide the data according to the size of the original data, and the sequence number (S #) is set at the same time as the address so that the recording order can be understood. Record on disc. For example, in the figure, when the recording command records data 1 of 40 blocks in length with LBA (logical block address) 0, the recording data is actually divided into 4 blocks of 10 blocks in length and the location of data disk 1 Data 10 and 1-1 having a length of 10 are recorded in 0 and 10, respectively, and data 1-3 and 1-4 having a length of 10 are recorded in locations 0 and 10 of the data disk 2, respectively.

At each recording location, data 1-1 to 1-4 were recorded at the same time as the value of the address LBA itself specified by the recording command. Data 2 is similarly divided and distributed on two disks. For this reason, however, since data 3 is originally 10 in length, even if it is further divided, the overhead increases, so it is not divided. Similarly, data 4 is divided but data 5 and 6 are not divided.
In the above example, an example is shown in which the disk is divided into two disks, but of course, it may be divided into four disks as in the example of FIG.

  When data is recorded on a plurality of disks, the data is actually stored in a temporary memory (cache) of each recording / reproducing apparatus. Since the transfer to the cache is performed at a sufficiently high speed (100 MB / s or more), after effectively transferring the data sequentially to the caches of multiple drives, the two drives transfer the data in each cache. Recording on each disk is performed in parallel. As a result of actually verifying recording performance using two drives, it was found that a recording speed about twice that of a single drive could be obtained.

  In FIG. 1, the arrangement of data on each disk is performed sequentially. That is, as shown in FIG. 3, data is arranged without a gap from the head side to the last side of the disk. Data recording is always performed continuously from the position next to the last recording position of each disk. Therefore, in this method, even if the same LBA is overwritten many times, the actual recording is recorded sequentially in another location, so that not only random access does not occur but the speed can be increased. Even if a write-once disk is used, pseudo-overwriting can be realized.

  When dividing and recording as shown in FIG. 1, an address conversion table indicating in which disk on which disk the final data of each LBA is actually recorded is created on the memory of the controller 51. When reading the recorded information, the address conversion table on the memory is used. The address conversion table is recorded on the disk when the disk is taken out or when an instruction from the host does not come. The address conversion table is recorded at the end of the recorded area when the disc is removed. When recording an address conversion table, in addition to information such as an identifier indicating that it is an address conversion table and the last recording time, a parity such as CRC is added to verify that the address conversion table itself is recorded normally. Record.

  At the time of reading, the validity of the address conversion table is verified by this identifier and parity. If the address translation table could not be recorded due to some trouble and a valid address translation table was not found at the time of reading, all data on the disk was scanned to obtain past virtual logical state information. The address conversion table can be restored by analyzing the sequence of the recorded commands, which is excellent in reliability. It is necessary to know in which order the recording commands are issued on the plurality of disks during this restoration, and the sequence number S # is used to analyze this recording command sequence and reconstruct the address conversion table. Use.

The arrangement method when adding LBA, that is, identification information or sequence number information to the recording data, is a method of recording the identification information or sequence number by occupying one sector as normal data, for example, as shown in FIG. There is a method of adding identification information or order information picture to the head. In this case, recording in an area such as RSV of a DVD that is not used for normal user data recording is efficient because the data capacity is not reduced.
FIG. 9 shows an example in which the identification information and the sequence number are arranged immediately after the data. In any case, the identification information and the sequence number may be arranged in combination with the data.

  A method for distributing data to a plurality of drives will be described with reference to FIG. FIG. 10 shows an operation example when data is equally distributed to two drives. If drive # 0 stagnate for reasons such as defect management, the drive # 1 cache is partially emptied, which is not very efficient. Therefore, by preferentially recording on the drive with more cache space while monitoring the free space of the drive cache in real time, the cache imbalance is eliminated and the maximum recording performance is always obtained.

  Further, when distributing data to a plurality of drives, important information such as file management information is recorded on the plurality of drives and multiplexed (mirrored). This has the merit of being able to improve the reliability of information that has a large influence when it is lost. In this case, the data to be mirrored is identified as a mirror by using the same sequence number. There are a method for determining whether to perform mirroring based on the type of command sent from the host and a method for automatically allocating according to the address (LBA) area. The latter is particularly effective in a file system in which the management area is arranged in a fixed area.

As shown in FIG. 11, the address table is simultaneously recorded on a plurality of disks. In this case, the same address table is recorded on a plurality of discs, thereby improving the read reliability of the address table.
There is also a method of recording the address table together on the nonvolatile medium HDD. In this case, since the address conversion information of a plurality of disks is handled collectively, it is preferable to check the consistency by recording the ID information of each disk on a nonvolatile medium.

The figure which shows the logic structure of the recording / reproducing method of this invention. The figure which shows the structure of the recording / reproducing system of this invention. The figure which shows the example of arrangement | positioning of the recording information of this invention. The block diagram of the conventional information recording / reproducing apparatus. The figure which shows the subject of the conventional optical recording and reproducing method. The figure which shows arrangement | positioning of the physical address information and recording data of the conventional optical recording / reproducing method. The figure which shows arrangement | positioning of the physical address information and recording data of the conventional optical recording / reproducing method. The figure which shows the example of the arrangement | positioning method of the identification information of this invention, order information, and data information. The figure which shows the example of the arrangement | positioning method of the identification information of this invention, order information, and data information. The figure explaining the example of operation | movement of this invention. The figure which shows the example of arrangement | positioning of the recording information of this invention. The figure which shows the effect of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Optical disk, 2 ... Optical head, 21 ... Light spot, 22 ... Light beam, 23 ... Objective lens, 24 ... Collimator lens, 25 ... Laser, 26 ... Detector, 27 ... Detector, 28 ... Beam splitter, 29 ... Hologram element, 31 ... Lens actuator, 41 ... Signal reproduction block, 51 ... Parallel transfer controller.

Claims (9)

An information recording method for recording or reproducing information on a plurality of information recording media via a plurality of information recording / reproducing means,
When recording information on the plurality of information recording media,
Selecting one of the plurality of information recording media;
At least a step of recording information at a recording position immediately after a position where information was recorded immediately before in the information recording area of the selected information recording medium, by combining address information for identifying recording data and recording data. A method for recording information, comprising:   The information recording method according to claim 1, further comprising a step of recording an address conversion table indicating a relationship between the address information and recording positions on the plurality of media on the recording medium.   3. The information recording method according to claim 2, wherein the address conversion table is recorded in a temporary storage unit in the recording apparatus and then transferred from the temporary storage unit to the recording medium.   4. The information recording method according to claim 2, wherein the address conversion table is recorded on a plurality of recording media.   2. The information recording method according to claim 1, wherein the step of selecting one of the plurality of information media is performed so as to average busyness of the plurality of information recording / reproducing means. An information recording method for recording or reproducing information on a plurality of information recording media via a plurality of information recording / reproducing means,
When recording information on the plurality of information recording media,
Selecting one of the plurality of information recording media;
In the information recording area of the selected information recording medium, address information for identifying the recording data, recording data, and a sequence number indicating the recording order of the recording data are recorded at the recording position immediately after the position where the information was recorded immediately before. An information recording method comprising a step of recording information as a set. Building an address conversion table from information recorded on a plurality of information recording media and storing it in a temporary storage means;
Identifying a recording position on a plurality of recording media of recording information of a target address using an address conversion table on the temporary storage means;
A method for reproducing information from a plurality of recording media, comprising at least a step of reading information on the identified recording position from a corresponding information recording medium. The step of constructing an address conversion table from the information recorded on the plurality of information recording media and storing it in the temporary storage means,
The address conversion table recorded on the plurality of information recording media is read and verified, and when the validity of the address conversion table is confirmed as a result of the verification, the address conversion table is stored in the temporary storage means,
As a result of the verification, when it is not possible to confirm that a valid address conversion table exists on a plurality of recording media, the address conversion is performed on the temporary storage means based on the address information and the order information recorded on the plurality of recording media. A method for reproducing information from a plurality of recording media, which is performed by reconstructing a table.   The address information for identifying the recording information is recording block information instructed from a host or higher-level information processing means or information obtained by converting the block information according to a certain rule. 2. The information recording method according to 1.

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