JP2008129619A - Data storage device and data storage method - Google Patents

Abstract

An object of the present invention is to provide a data storage device and a data storage method for efficiently performing a copying operation of a magnetic tape.

In the present invention, valid data is selected from data stored in a first storage medium by a control means, copied to a second storage medium, and the second record is recorded in the valid data. A data storage device is used which performs control to copy data that has not been copied to the medium to the third storage medium. Copy time can be shortened and resources of the storage medium can be used effectively. In addition, the storage medium is a magnetic tape, and the data that has not been copied into the second recording medium is identified as data in which the end of the second recording medium is detected during copying of the data. Thus, the data can be automatically copied to the third storage medium.

[Selection] Figure 3

Description

  The present invention relates to a data storage device and a data storage method for copying data from one storage medium to another one of the same kind of storage medium for duplication of storage data in a computer system.

  Conventionally, when copying data of a storage medium provided in a computer system to a storage medium provided in another terminal, all of the copy sources are used by using the medium attributes (model, model name, file capacity) of the two media. Check if the data is copied to the copy destination medium. If the copy destination capacity is insufficient, display a message to the copy operator and cancel the copy or prepare multiple storage media. There is a method of informing (see Patent Document 1).

Further, in a magnetic tape device that is used repeatedly, as a method of reducing the invalid storage area and effectively using the storage area of the magnetic tape, the data is stored on the magnetic tape as data of different generations in the order of storage timing. Storage of new generation data is based on the detection of the tape mark indicating the end of each generation of data, and the old generation data is erased only when it is shorter than the old generation data length that can be deleted. There is a method of storing (see Patent Document 2).
Japanese Patent Laid-Open No. 04-195765 Japanese Patent Laid-Open No. 06-139650

  In the background art described above, the method of Patent Document 1 that uses the medium characteristics of the storage medium is complicated because the copy operator needs to be operated step by step when the copy source data cannot fit in the copy destination.

  Further, only when the data length of the new generation is shorter than the data length of the old generation that is allowed to be erased, the method of Patent Document 2 for storing the data of the new generation displays an error when the data of the new generation cannot be contained, A burden is placed on the copy operator.

  Furthermore, when there is a defective portion that cannot be stored on the copy destination tape, the case where all the copy source data does not enter the copy destination even though the storage capacities of the copy source and the copy destination are formally equal is shown in FIG. explain.

In FIG. 1, 101 is a copy source tape, D101 ₁ , D101 ₃ , D101 ₄ is a block of valid data, D101 ₂ is a block of invalid data, A101 _x is a non-writable part, 102 is a copy destination tape, D102 ₁ , D102 ₃ , D102 ₄ is valid data block, D102 ₂ shows blocks of invalid data, a 102 _x is unwritable area, a 102 _y has a defect area, respectively.

The conventional copy method attempts to copy all of the data blocks D101 _{1 to} D101 ₄ stored in the copy source tape 101 in FIG. However, the copy destination tape 120, due to the presence of faulty areas A 102 _y can not copy, becomes unwritable since blocks D102 ₄ data corresponding to the block D101 ₄ of copy source data does not fit.

  In this case, the method described in the background art has a problem that the frequency of the operator replacing the copy destination tape again and repeating the copy operation increases.

  Accordingly, one object of the present invention is to provide a data storage device and a data storage method for efficiently performing a magnetic tape copy operation.

  In addition, it is a result derived | led-out by each structure shown in the best form for implementing invention mentioned later not only the said objective, Comprising: The effect which is not acquired by the prior art is also one of the other objectives of this invention. Can be positioned.

(1) In the present invention, effective data is selected from the data stored in the first storage medium by the control means, copied to the second storage medium, and the second recording medium among the effective data A data storage device is used in which control is performed to copy data not copied into the third storage medium. Copy time can be shortened and resources of the storage medium can be used effectively.

  In addition, the storage medium is a magnetic tape, and the data that has not been copied into the second recording medium is identified as data in which the end of the second recording medium is detected during copying of the data. Thus, the data can be automatically copied to the third storage medium.

In the case of a data storage device that stores the same data in at least two storage media, when one of the storage media is damaged, the data of the other storage media storing the same data is stored in another normal storage. By copying to the medium, it is possible to store the same data in at least two storage media and reconstruct the duplex data storage (hereinafter referred to as “rebuild”), thereby improving the reliability of data storage. .
(2) In the present invention, the step of storing the same data in the first storage medium and the second storage medium, and when one of the storage media is damaged, the other data is stored in the other storage medium storing the same data. Selecting valid data from stored data, copying the valid data to a normal third storage medium, and detecting the end of the third storage medium while the copying is not completed When the data is not copied, the data is copied to another normal fourth storage medium. The reliability of data storage can be ensured, the copy time can be shortened when the storage medium fails, and the resources of the storage medium can be used effectively.

  According to the present invention, it is possible to provide a data storage device and a data storage method that can execute a copy process of data stored on a magnetic tape in a short time and can effectively use resources of the magnetic tape.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Example)
In the embodiment, when one storage data is damaged in a data storage device in which the same data is duplicated and stored on two magnetic tapes, new invalid data is removed from the normal magnetic tape except old invalid data. Select only to copy to the new destination tape.

  The configuration of the data storage device in the embodiment is shown in FIG.

2, 201 is a data storage device, 202 is a hard disk device, 203 is a hierarchical control server, 204 is a tape library device, 204 ₁ is tape A, 204 ₂ is tape B, 204 ₃ is tape C, and 204 _N is tape N. 205 denote host computers.

  In FIG. 2, a data storage device 201 stores data by assisting a hard disk 202 that stores necessary data in a host computer 205.

  If the data processed by the host computer 205 increases, the storage capacity of the hard disk device 202 may be exceeded. In this case, the hard disk device 202 stores data on the tape in the tape library device 204 via the hierarchical control server 203.

Within the tape library device 204, to ensure the reliability of data storage, the same content data, for example, stored in the tape A204 ₁ and tape B 204 _2, 2 duplicated data storage is performed.

  Data stored on the tape of the tape library apparatus 204 may be partially destroyed by repeated read / write operations.

For example, when the data stored on the tape B 204 ₂ is destroyed, the data stored on the tape A204 _1, then copied to the new tape C204 _3, to reconstruct (rebuild) the duplexed data storage.

The processing operation for rebuilding the data on tape A204 ₁ to tape C204 _{3 according} to the present invention will be described with reference to FIGS.

3, the same components as those in FIG. 2 are denoted by the same reference numerals, D301 ₁ , D301 ₃ , D301 ₄ are valid data blocks, D301 ₂ is invalid data blocks, A301 _x is a tape end portion, D302 ₁ , D302 ₃ and D302 ₄ are blocks of valid data, A302 _x is a tape end portion, and A302 _y is a defective area.

  4, S401 is a step of starting rebuilding, S402 is a step of searching for copy source invalid data, S403 is a step of determining whether there is invalid data at the copy source, and S404 is a step of excluding invalid data from the copy target. S405 is a step of copying data to the copy destination, S406 is a step of determining whether or not the end of the copy destination has been detected, S407 is a step of copying the remaining data from the copy to a copy destination of another tape, and S408 is a rebuild. Each step that ends is shown.

In this embodiment, the time, etc. that implement the read and write data using a tape library device 204, it shows a rebuild process when the data corruption in the tape B 204 ₂ occurs.

  The hierarchical control server 203 controls each step of the rebuild processing operation described below.

In step S401, rebuilding of the data of the tape A204 ₁ to the tape C204 ₃ is started. In step S402, it searches the invalid data from the data of the copy source tape A204 _1. In step S403, it is determined whether the invalid data in the data of the copy source tape A204 ₁ exists. In this determination, the hierarchical control server 203 manages a flag indicating validity / invalidity of each block data stored on the tape in the tape library device 204, and the determination is made by examining this flag. In the example of FIG. 3, the flag for a data block D 301 ₂ of the copy source tape A204 ₁ indicates invalid.

In step S404, excluded from the block of data of the copy source tape A204 _1, from the copy target block of data D 301 ₂ as invalid data. In step S405, the data blocks D301 ₁ , D301 ₃ , and D301 ₄ obtained by excluding the data block D301 ₂ from the data blocks of the copy source tape A204 ₁ are copied to the copy destination tape C204 ₃ .

In this copy, each tape used by the tape library apparatus 204 uses the LTO (Linear Tape-Open) standard, and when writing to the LTO standard copy destination tape C204 ₃ , the defective area A 302 y is detected as being unstorable. automatically skipped copy, data block D 301 ₄ data of the copy source tape A204 ₁ is written to the destination tape C204 ₃ as a block D302 ₄ data.

In step S406, it writes all blocks of valid data of the copy source tape A204 ₁ is the destination tape C204 _3, when the end portion A 302 _x is not detected, ends the rebuild no next, at step S408.

If, in step S406, termination A 302 _x destination tape C204 ₃ is (not shown in FIG. 3) when it is detected while the copy is not completed, yes, and the process proceeds to step S407.

In step S407, still block of data that has not been copied in the copy source tape A204 ₁ is copied to the new tape under the control of the control server 203. The detection of the copy destination tape C204 ₃ of the terminal portion A 302 _x is determined the flow returns to step S406.

The above flow, written all valid data blocks of the copy source tape A204 ₁ is the destination tape C204 _3, 2 duplicated data storage is completed.

  In the rebuild according to the present invention shown in FIG. 3, the block of data to be copied is limited to only valid data compared with the conventional rebuild shown in FIG. Processing can be executed in a short time, and tape resources can be used effectively.

It is a figure which shows the example of the conventional rebuild. It is a figure which shows the structure of a data storage device. It is a figure which shows the Example of the rebuild by this invention. It is a figure which shows the example of a flow of the rebuild process by this invention.

Explanation of symbols

101 Copy source tape 102 Copy destination tape 201 Data storage device 202 Hard disk device 203 Hierarchical control server 204 Tape library device 204 ₁ tape A
204 ₂ Tape B
204 ₃ Tape C
204 _N tape N
205 Host computer

Claims (6)

Data storage means comprising a plurality of storage media for storing data;
Data that is selected from the valid data stored in the first storage medium of the storage medium, copied to the second storage medium of the storage medium, and that is not copied in the second recording medium among the valid data Control means for performing a control of copying to a third storage medium of the storage medium;
A data storage device comprising:   2. The data according to claim 1, wherein identification of data that has not been copied to the second recording medium is data in which an end portion of the second recording medium is detected during copying of the data. Storage device.   The data storage device according to claim 1, wherein the storage medium is a magnetic tape.   The data storage device according to claim 1, wherein the data storage device stores the same data in at least two storage media.   When one of the storage media is damaged, the data of another storage medium storing the same data is copied to another normal storage medium, and the same data is stored in at least two storage media. The data storage device according to claim 1. Storing the same data in the first storage medium and the second storage medium;
Selecting one of the data stored in another storage medium storing the same data when one of the storage media is damaged;
Copying the valid data to a normal third storage medium;
Copying the data not copied in the valid data to another normal fourth storage medium when the end of the third storage medium is detected while the copying is not completed;
A data storage method including:

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