JP2010165257A - Apparatus and method for recording data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for recording data at high recording speed and high reliability, and a method for recording data. <P>SOLUTION: The apparatus for recording data includes: an interface 40 in which files are input; a plurality of striping groups SG including a plurality of recording media M for recording the files; an SG management table 23 which records information about free spaces of the striping groups SG for each striping group; a file management processing means 21 for determining one of striping groups SG for recording the files input from the interface 40 by referring to information in the SG management table 23; and a data processing means 10 for recording the files into one striping group SG determined by the file management processing means 21. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to high reliability of a recording apparatus that records data at high speed.

  In recent years, there have been frequent opportunities to handle large volumes of data. In particular, as the definition of video data increases, the volume of video data has become enormous. When such a large amount of data is recorded on a recording medium, the recording time becomes longer. Therefore, a technique for recording at higher speed is required.

  Striping or RAID (Redundant Arrays of Inexpensive) in which a plurality of recording media are prepared as a technique for recording at high speed, and one data (for example, data having a file name “A”) is distributed and recorded on the plurality of recording media. There is a technology called Disks). This striping technique is known as a technique capable of recording one data at a higher speed than recording one data on one recording medium. Further, as the number of recording media for distributed recording is increased, the recording speed can be further increased.

  By the way, as a technique for shortening the time from the read request to the start of reading when reading the data recorded on the recording medium, for example, Patent Document 1 is known. In Patent Document 1, in a shared storage distributed multimedia server system in which a plurality of disks are shared by a plurality of servers in a network, when scheduling is performed to prevent a plurality of servers from accessing the disks at the same time, reading is performed by scheduling. It is described that these disks are grouped in order to solve the problem that the time from the request to the actual start of reading becomes long.

  However, when one piece of data is distributedly recorded on a plurality of recording media, if one of the recording media fails, the portion of data recorded on the failed recording medium cannot be read, so the name “A” Data around the file is lost. As a result, the file named “A” cannot be read. Moreover, if not only the file “A” but also other files are recorded, these files are of course distributedly recorded, so that all the files cannot be read due to the failure of only one recording medium. It will be possible.

  Therefore, an error correction code that is known as a technique called RAID 3, RAID 4, or RAID 5 and that supplements data recorded on a recording medium that cannot be read is used for distributed recording.

  For example, in RAID4, assuming that four recording media are prepared, when performing striping on these recording media, one piece of data with the file name “A” is divided into a large number of pieces of data. Are distributed and recorded on three recording media. At this time, the remaining one recording medium is recorded with data for interpolating the data recorded on the other three recording media. A recording medium for recording data for interpolating this data is often called a parity disk. As a specific usage of this parity disk, when one of the three recording media on which the file named “A” is recorded fails, the data recorded on the two normal recording media The data recorded on the failed recording medium is interpolated from the data recorded on the parity disk.

Japanese Patent Laid-Open No. 10-134485

  However, when a plurality of recording media fail or when the parity disk fails, all of the data recorded on these recording media cannot be read, and reliability is lacking. Further, the above Patent Document 1 does not describe a measure for preventing data from being unreadable when a part of recording media used for distributed recording fails.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a data recording apparatus and a data recording method with high recording speed and high reliability.

  In order to achieve the above object, a data recording apparatus according to the present invention includes an interface unit to which a file is input, a plurality of striping groups including a plurality of recording media for recording the file, and information relating to the free capacity of the striping group. SG management table for recording each striping group, and file management processing means for determining one striping group for recording the file input from the interface unit with reference to the information of the SG management table And data processing means for recording the file in one striping group determined by the file management processing means.

  In order to achieve the above object, a data recording method according to the present invention includes a capacity determination step for determining the capacity of an input file, and a striping group having a free capacity larger than the capacity determined in the capacity determination step. The free capacity determination step for determining with reference to the SG management table for recording the free capacity of the striping group and the number of recordings of the striping group, and the free capacity determination step with reference to the SG management table And a recording destination determining step for determining a striping group having the smallest number of recordings among the striping groups as a recording destination.

  In order to achieve the above object, the data recording method according to the present invention determines a striping group having a free capacity by referring to an SG management table that records the free capacity of the striping group and the number of recordings of the striping group. A vacancy determination step, and a recording destination determination step of determining, as a recording destination, a striping group having the smallest number of recordings among the striping groups determined in the vacant capacity determination step with reference to the SG management table. Data recording method.

  According to the data recording apparatus of the present invention, the recording speed is high and the reliability can be further improved.

1 is a functional block diagram of a data recording apparatus according to an embodiment of the present invention. The figure which shows an example of the file management table with which the file management part which concerns on one embodiment of this invention was equipped. The figure which shows an example of the file management table with which the file management part which concerns on one embodiment of this invention was equipped. The flowchart which shows the process which records the file to a striping group when the capacity | capacitance of the input file which concerns on one embodiment of this invention is known. The flowchart which shows the process which records the file on a striping group, when the capacity | capacitance of the input file which concerns on one embodiment of this invention is unknown.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a functional block diagram of a data recording apparatus showing an embodiment of the present invention.
The data recording apparatus 100 includes a data processing unit 10 that processes input data and output data, a file management unit 20 that manages files, a recording unit 30 that records files, and an interface unit 40 that inputs and outputs files. Have

  The recording unit 30 is provided with a plurality of striping groups SG1, SG2, and SG3 each having a plurality of recording media as one group. In one striping group SG (common to SG1 to SG3), for example, a plurality of recording media M1, M2,... Controllers C1, C2, and C3 that control the physical address of the recorded data, such as whether to record to the physical address of the recording medium, are provided. The striping group SG is distributed and recorded on a plurality of recording media M (common to M1 to M9) provided in one striping group SG when a file is recorded in the striping group, and further an error correction code is also recorded. The

  The file management unit 20 includes a file management table 22 for recording information for managing in which striping group SG a file is recorded, an SG management table 23 for recording free space and the number of recordings of the striping group SG, A file management processing unit 21 that searches and updates information in the management table 22 and the SG management table 23 is provided.

  When a file is input from the interface unit 40, the data processing unit 10 instructs the file management processing unit 21 to search for a striping group SG having a free space, and the file management processing unit 21 reads the SG management table 23. A striping group SG having a free capacity is determined by referring to the table. The file management processing unit 21 that has determined the striping group SG having free space determines the striping group SG having free space as the recording destination striping group SG, and instructs the data processing unit 10 of the recording destination. The data processing unit 10 records the file in the striping group SG designated as the recording destination. Of the plurality of recording media M included in the striping group SG designated as the recording destination, which part of the file is to be recorded at which position of which recording medium M is the controller C (C1 provided in the striping group SG). To C3) is distributedly recorded, and information on which recording medium M is recorded at which position is recorded.

  When reading a file, when an instruction to read the file is given from a man-machine interface (not shown) or a higher-level application, the data processing unit 10 determines in which striping group SG the file is recorded. The file management processing unit 21 searches the file management table 22 to determine in which striping group SG the file is recorded, and reads the data processing unit 10 from the striping group SG. Instruct. The data processing unit 10 requests the instructed striping group SG to read the file, and determines which position on which recording medium M the controller C with which the striping group SG is actually recorded reads. ing.

  Here, the file management table 22 and the SG management table 23 will be described with reference to FIGS.

  FIG. 2 shows an example of the file management table 22 provided in the file management unit 20. In the file management table 22, a file name for identifying a file recorded in the recording unit 30 and a striping group name for identifying the striping group SG in which the file is recorded are recorded in association with each other. In the example of the file management table 22 shown in FIG. 2, the file with the file name “FILE1” is associated with “SG2” indicating that it is recorded in the striping group 2. The file with the file name “FILE2” is associated with “SG3” indicating that it is recorded in the striping group 3. Similarly, “FILE3” is associated with “SG1”.

  When a new file is recorded in the recording unit 30, the information is recorded in the file management table 22. When a file recorded in the recording unit 30 is deleted, the file management table 22 stores the information. The file management processing unit 21 updates the information so as to delete the information.

  In the file management table 22, a file name for identifying a file and a striping group name for identifying the striping group SG in which the file is recorded are recorded in association with each other. By referring to the management table 22, when the file is read, the striping group SG to be read can be determined.

  FIG. 3 shows an example of the SG management table 23 provided in the file management unit 20. In the SG management table 23, for each striping group SG, information on the free capacity indicating how much free capacity is available at that time, and information on the number of recordings indicating the number of times recorded in the striping group SG are recorded. Yes. In the example of the SG management table 23 shown in FIG. 3, “SG1” indicating the striping group 1 records that the free capacity is “10M” and the recording count is “10986”. In addition, “SG2” indicating the striping group 2 has a free capacity of “30M” and a recording count of “5931”, and similarly, the striping group 3 has a free capacity of “5M” and a recording count of “8142”. It is recorded that.

  Since the SG management table 23 records the free capacity and the number of recordings for each striping group SG at that time, when a file is recorded in the recording unit 30, the SG of the striping group SG that recorded the file is recorded. The file management processing unit 21 updates the free space information and the recording count information. When the file recorded in the recording unit 30 is deleted, the file management processing unit 21 updates the information on the free capacity of the striping group SG from which the file has been deleted.

  In the SG management table 23, for each striping group, the free capacity of the striping group SG and the number of times of recording in the striping group SG are recorded in association with each other, so when recording a file to the recording unit 30, The file management processing unit 21 can determine which striping group should be recorded with reference to the SG management table 23.

  In the SG management table 23 shown as an example in FIG. 3, the free capacity and the number of times of recording at that time are recorded for each striping group SG. However, instead of the free capacity, the capacity of the recording medium M and The recording capacity at that time may be recorded.

  Next, an example of processing for recording an input file will be described with reference to FIG. FIG. 4 is an example of a flowchart showing processing when the capacity of the input file is known.

  First, when a file is input from the interface unit 40, the data processing unit 10 determines the capacity of the file (S101). The data processing unit 10 instructs the file management processing unit 21 to search whether there is a striping group SG having a free capacity larger than the capacity of the file (S102). The file management processing unit 21 instructed to search refers to the SG management table 23 and determines whether or not there is a striping group SG having a free capacity larger than the capacity of the input file. At this time, if there is no striping group SG whose free capacity is larger than the capacity of the input file, recording is not performed, a display or warning such as “cannot be recorded” is displayed, and the process is terminated. If there is a striping group whose free capacity is larger than the capacity of the input file, the file management processing unit 21 determines whether the number of the striping group SG is one or more (S103).

  If there are a plurality of recording groups, the striping group SG having the smallest number of recordings is determined as the recording destination (S104). When the recording destination striping group SG is determined, the file management processing unit 21 instructs the determined striping group SG as a recording destination, and the data processing unit 10 records a file in the striping group SG. If it is determined in step S103 that there is one striping group having a free capacity larger than the capacity of the input file, that striping group SG is determined as the recording destination (S105). The method for recording the file in the determined striping group SG is performed in the same manner as in step S104.

  When the process S104 or S105 is completed, the file management processing unit 21 updates the SG management table 23 in order to set the free capacity and the number of recordings of the striping group SG recorded in the process S104 or S105 to the current values. Then, in order to manage in which striping group SG the file is recorded, the file management processing unit 21 updates the file management table 22 and ends (S106).

  As described above, since one file is recorded in one striping group SG, even when the recording medium M in another striping group SG fails, the file is recorded in the non-failed striping group SG. Files can be read, and the number of files lost when the recording medium M fails can be reduced. Even when the recording medium M in the striping group SG fails, an error correction code is recorded for each striping group, so that depending on the failure range of the recording medium M, it is recorded on the failed recording medium M. Data can be interpolated. Further, when the striping group SG for recording the file is determined, the number of recordings for each striping group SG is also used as a judgment material, and recording is performed in a striping group with a small number of recordings. In the case of M, the life of the recording medium M can be extended.

(Modification of file recording process)
In the example of the flowchart of FIG. 4, the process of determining the recording striping group SG when the capacity of the file to be recorded in the recording unit 30 is known has been described. Here, as a modification thereof, an example of how to determine the recording destination striping group SG when the capacity of the file to be recorded in the recording unit 30 is unknown is shown.

  FIG. 5 is an example of a flowchart illustrating processing when the capacity of a file to be recorded in the recording unit 30 is unknown.

  First, when a file is input (S201), the data processing unit 10 instructs the file management processing unit 21 to search for a striping group SG having a free capacity (S202). If there is no striping group SG with free capacity, the file cannot be recorded, so a display or warning such as “no free SG” is displayed and the process is terminated. In processing S202, when there is a striping group SG having a free capacity, it is determined whether there is one or more striping groups SG (S203). The subsequent processes S204 to S206 are the same as the processes S104 to S106, and thus the description thereof is omitted.

  Thus, even when the capacity of the file is unknown at the time when the file to be recorded is input to the recording unit 30, the same effect as when the capacity of the file is known can be obtained.

  As described above, by recording one file in one striping group SG, the recording speed is high by performing distributed recording on a plurality of recording media M provided in the striping group SG. Files that disappear when the recording medium M fails can be reduced. As a result, the reliability of file recording can be improved.

  Further, when the striping group SG for recording the file is determined, the recording frequency for each striping group SG is also used as a judgment material so that the recording is performed in the striping group with a small recording frequency. In the case of M, the life of the recording medium M can be extended.

  In addition, this invention is not limited to the above structure, A various deformation | transformation is possible. For example, the number of striping groups SG is three in the embodiment. However, four or more striping groups SG may be provided, and the number of recording media M included in one striping group SG is three as shown in the embodiment. It is not limited to, You may make it provide four or more.

DESCRIPTION OF SYMBOLS 10 ... Data processing part, 20 ... File management part, 21 ... File management processing part, 22 ... File management table, 23 ... SG management table, 30 ... Recording part, M, M1-M9 ... Recording medium, SG, SG1-SG3 ... Striping group, C, C1 to C3 ... Controller

Claims (4)

An interface part to which a file is input;
A plurality of striping groups comprising a plurality of recording media for recording the files;
An SG management table for recording information on the free capacity of the striping group for each striping group;
File management processing means for referring to the information in the SG management table and determining one striping group for recording the file input from the interface unit;
A data recording apparatus comprising: data processing means for recording the file in one striping group determined by the file management processing means. The SG management table records the number of recordings for each striping group,
The file management processing means refers to the SG management table, and determines, from among the striping groups having free capacity, a striping group having the smallest number of recordings for each striping group as a recording destination. Item 4. The data recording device according to Item 1. A capacity determination step for determining the capacity of the input file;
A free capacity determining step of determining a striping group having a free capacity larger than the capacity determined in the capacity determining step with reference to an SG management table that records the free capacity of the striping group and the number of recordings of the striping group;
A data recording method comprising: referring to the SG management table; and a recording destination determining step of determining, as a recording destination, a striping group having the smallest number of recordings among the striping groups determined in the free capacity determining step. . An empty determination step of determining a striping group having an empty capacity with reference to an SG management table that records the empty capacity of the striping group and the number of recordings of the striping group;
A data recording method comprising: referring to the SG management table; and a recording destination determining step of determining, as a recording destination, a striping group having the smallest number of recordings among the striping groups determined in the free capacity determining step. .

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