JP7310110B2 - storage and information processing systems; - Google Patents

Description

The present invention relates to storage and systems that manage data using metadata.

In recent years, methods of managing data using storage media such as SSDs (solid state drives) and HDDs (hard disk drives) have become mainstream. A storage device including such a storage medium accesses data on the storage medium using internal access means and metadata in response to a request from an external device.

Metadata includes position information indicating the storage position of data on the storage medium. Specifically, when the access means in the storage device receives a data read request from an external device, it refers to the location information included in the metadata and specifies the storage location of the data on the storage medium. I am reading data from. Further, when receiving a data write request from an external device, the access means in the storage device writes the data onto the storage medium, and writes the position information indicating the position where the data is written in the metadata.

Note that such a storage device often includes one piece of metadata per storage device.

Patent document 1 is mentioned as an example of the technique of managing data using metadata. In the file system described in Patent Document 1, metadata is stored in a predetermined area on the storage device. The metadata includes map information that associates the file data with the location where the file data is stored, and various other information. When writing file data to the storage device, first, the metadata group stored in a predetermined area is read, the metadata group is analyzed, and the location to write the file data is specified from the analysis result and the size of the file data. When the write position is specified, metadata regarding the file data is generated, and the generated metadata is written in a predetermined area of the storage device. At this time, the metadata includes map information indicating in which position (block) the file data is actually stored. It also writes the file data to the storage device according to the map information.

In addition, as an example of technology for speeding up the reading of metadata, Japanese Patent Application Laid-Open No. 2002-300001 is cited. The technology described in Patent Document 2 integrates metadata that can be integrated into one physical volume among metadata for volume group management stored in each physical volume, and performs the integration. By reading metadata from metadata, the speed of reading metadata from each physical volume is increased. Further, in the technique described in Patent Document 2, copies of metadata 1 to n arranged at the beginning of the original physical volume are used as consolidated metadata.

JP 2015-179328 A Japanese Patent Application Laid-Open No. 2004-265110

By the way, in a storage device that manages data using metadata, there is a case where data acquired in real time is written to a storage medium while data written in the past is read from the storage medium for analysis. There is In such processing, data is often read and written using a plurality of access means in parallel. When multiple access means write data to one piece of metadata, exclusive control or the like is performed on the metadata in order to prevent data destruction due to write competition.

Therefore, while a specific access means is writing position information to metadata, other access means cannot access the metadata.

In the techniques described in Patent Documents 1 and 2, when a specific access means writes data to metadata including map information, other access means cannot access the metadata. become unable. Therefore, the techniques described in Patent Documents 1 and 2 cannot efficiently access metadata.

The present invention can solve the above problems and provide a storage and information processing system that can efficiently access metadata.

A storage according to the present invention comprises a storage medium for storing data, a plurality of access means for performing processing of writing data to the storage medium and processing of reading data from the storage medium, and first storage means for storing first metadata including position information indicating a position where data is written; and second storage means for storing second metadata including position information indicating a data storage position in the storage medium 2 storage means, wherein the plurality of access means reads data from the storage medium using the second metadata.

An information processing system according to the present invention comprises a storage medium for storing data, a first server for writing data to the storage medium, a second server for reading data from the storage medium, and the first server comprising: A first server stores first metadata including location information indicating a location where data is written in the storage medium, and the second server includes location information indicating a storage location of data in the storage medium. Second metadata is stored and data is read from the storage medium using the second metadata.

The present invention provides a storage and information processing system that can efficiently access metadata

2 is a diagram showing the configuration of a storage 1; FIG. 4 is a flow chart showing a process of writing data; 4 is a flow chart showing a process of reading data; 2 is a diagram showing the configuration of a storage device 10; FIG. 4 is a flow chart showing the operation of update processing; 5 is a diagram showing a specific example of write metadata 50. FIG. 6 is a diagram showing a specific example of read metadata 60. FIG. 4 is a conceptual diagram of update processing; FIG. 3 is a diagram showing the configuration of a storage device 11; FIG. 3 is a diagram showing the configuration of a storage device 12; FIG. It is a figure which shows one example of the computer which implement|achieves this invention.

<First embodiment>
[composition]
A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the configuration of a storage 1 in the first embodiment.

The storage 1 comprises a storage medium 2 , first access means 3 , second access means 4 , first storage means 5 and second storage means 6 . The storage 1 can be applied to techniques for analyzing data accumulated in the past while accumulating data, such as weather forecast, stock price trend analysis, or product sales analysis.

The storage medium 2 is a medium for storing data. Specifically, the storage medium 2 is a medium to which data can be written and read. Specific examples of the storage medium 30 include SSD, HDD, flash memory, SD card, eMMc (embedded Multi Media Card), etc., but the present invention is not limited to these.

The first access means 3 is means for accessing the storage medium 2 and the first storage means 5 . Upon receiving a data write request from an external device, the first access means 3 writes the data in the storage medium 2 . When writing data to the storage medium 2, the first access means 3 writes the data to a position in the storage medium 2 different from the position where the data is already stored. A detailed description of the process of writing data to the storage medium 2 by the first access means 3 will be given later.

A second access means 4 is means for accessing the storage medium 2 and the second storage means 6 . The second access means 4 reads data from the storage medium 2 upon receiving a data read request from an external device. For example, the first access means 3 and the second access means 4 are configured by processors or the like in the storage 1 . However, the first access means 3 and the second access means 4 may have any configuration as long as they can communicate with the external device and the storage medium.

The first storage means 5 stores first metadata including position information indicating the position where the first access means 3 has written data to the storage medium 2 . When data is written to the storage medium 2, the first access means 3 writes position information indicating the position where the data is written in the first metadata. Metadata is a conversion table that converts a logical address of data requested by an external device into a physical address in the storage medium 2 . A specific example of position information will be described later.

The second storage means 6 stores second metadata including position information indicating the storage position of data in the storage medium 2 . Note that the first storage unit 5 and the second storage unit 6 may have any configuration as long as they can store metadata, such as memory. When reading data from the storage medium 2, the second access means 4 uses the second metadata stored in the second storage means 6 to identify the location where the data is stored, Read the data from The location information of the first metadata is updated to the location information of the second metadata at a specific timing. A specific example of specific timing will be described later.
[motion]
Next, main operations in the first embodiment of the present invention will be described.

FIG. 2 is a flow chart showing the process of writing data.

When the first access means 3 receives a data write request from an external device (S1), the first access means 3 writes the data in the storage medium 2 (S2).

When data is written to the storage medium 2, the first access means 3 writes position information indicating the position where the data is written in the first metadata (S3).

FIG. 3 is a flow chart showing the process of reading data.

When the second access means 4 receives a data read request from an external device (S11), it uses the second metadata stored in the second storage means 6 to identify the location where the data is stored. (S12).

The second access means 4 uses the specified position to read the data requested to be read from the storage medium 2 (S13).

As a result, the present invention according to the first embodiment can efficiently access metadata.

The reason is that the storage 1 includes a storage medium 2 for storing data, a first access means 3 for writing data to the storage medium 2, a second access means 4 for reading data from the storage medium 2, and a first access means 4 for reading data from the storage medium 2. first storage means 5 for storing first metadata including position information indicating the position where data is written in the storage medium 2 by the access means 3; 2, and the second access means 4 reads data from the storage medium 2 using the second metadata.
<Second embodiment>
[composition]
A second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a diagram showing the configuration of the storage device 10 in the first embodiment.

The storage device 10 includes a storage medium 30 , access means 40 , write metadata 50 , read metadata 60 and update means 70 .

The external device 20 issues a data write request, a data read request, or the like to the access means 40 . The data write request and read request include information indicating the capacity of the data and the location of the data. The external device 20 includes a device such as a host computer. Note that the external device 20 may be any device as long as it can communicate with the storage device 10 . As shown in FIG. 4, the storage device 10 can be connected to multiple external devices 20 .

The storage medium 30 is a medium to which data can be written and read. Specific examples of the storage medium 30 include SSD, HDD, flash memory, SD card, eMMc, etc., but the present invention is not limited to these. Moreover, the storage medium 30 may combine a plurality of media to form a RAID (Redundant Array of Inexpensive Disks), or may use a single medium.

The access means 40 accesses the storage medium 30, the metadata for writing 50, and the metadata for reading 60, and writes data or reads data.

Specifically, when receiving a data write request from the external device 20 , the access means 40 writes the data to the storage medium 30 and writes the position information indicating the position where the data is written to the write metadata 50 .

When the access unit 40 writes data to the storage medium 30, the data is written to a position different from the position where the data is already stored. Specifically, when the access means 40 receives a request to write data to a specific position, if the data has already been written to the specific position, it does not overwrite the data. write data to If data that has already been written to the storage medium 30 is overwritten, the reading metadata 60 may contain position information about the data before being overwritten instead of the overwritten data. be. In other words, if the storage medium 30 is overwritten, the position information contained in the read metadata 60 and the position where the data is actually written will become inconsistent, resulting in an inconsistency in the position information when reading the data. Doing so may cause malfunction. Therefore, the process of writing data by the access means 40 as described above is effective in preventing the inconsistency. Note that the access means 40 may write data from the continuation of the position where the data was last written to the storage medium 30 . The access means 40 may use metadata to grasp the position, or may separately prepare a memory for storing the last written position and use the memory. However, the access means 40 is not limited to this method, and any method may be used as long as the data can be written to a location different from the location where the data is already stored.

If the capacity of the storage medium 30 becomes insufficient due to the access means 40 writing data without overwriting, a new medium is added.

As described above, the storage device 10, which does not overwrite the storage medium 30, accumulates data such as weather forecast, stock price trend analysis, product sales analysis, etc., while storing data accumulated in the past. It is particularly effective when applied to the technique of analyzing. This is because the storage device 10 does not overwrite the data accumulated in the past, so all the data is accumulated in the state when it was stored in the storage medium 30 .

When the external device 20 issues a data read request, the access means 40 accesses the read metadata 60, refers to the position information included in the read metadata 60, and responds to the read request. Locate data. The access means 40 reads the data corresponding to the read request from the storage medium 30 using the specified position.

Although FIG. 4 illustrates a configuration in which the storage device 10 includes three access means 40, the present invention is not limited to this. For example, the storage device 10 can contain two or more access means 40 .

The write metadata 50 includes location information indicating the location where the access means 40 has written the data to the storage medium 30 . Note that the write metadata 50 may be stored in storage means such as a buffer or memory.

The read metadata 60 includes position information indicating the storage position of the data in the storage medium 30 . As shown in FIG. 4, the storage device 10 can contain multiple pieces of read metadata 60 . In FIG. 4, two reading metadata 60 are illustrated as an example, and the position information included in each of the two reading metadata 60 is the same. Although FIG. 4 illustrates a configuration in which the storage device 10 includes two pieces of read metadata 60, the present invention is not limited to this. For example, the storage device 10 may contain one or more read metadata 60 .

Only the access means 40 that has received a data read request from the update means 70 and the external device 20 can access the read metadata 60 . Note that the read metadata 60 may be stored in storage means such as a memory.

The updating means 70 accesses the write metadata 50 and the read metadata 60 and updates the position information included in the read metadata 60 . Specifically, the updating means 70 accesses the write metadata 50 at a specific timing, and uses the location information included in the write metadata 50 to update the location information included in the read metadata 60. (hereinafter referred to as update processing).

Note that the update process may be a process of adding the position information newly written to the write metadata 50 from the previous update to the read metadata 60 as a difference, or may be a process of adding the position information to the read metadata 60. It is also possible to copy all the position information that is stored to the read metadata 60 . The specific timing indicates the timing at which a read request is received from the external device 20, at regular time intervals, at specific times, or at specific times. A detailed description of the updating process performed by the updating means 70 will be given later.
[motion]
Next, main operations in the second embodiment of the present invention will be described.

FIG. 5 is a flowchart showing the operation of update processing.

At a specific timing (Yes in S21), the updating means 70 accesses the write metadata 50 (S22).

The update unit 70 updates the read metadata 60 using the position information included in the write metadata 50 (S23).
[Concrete example]
A main specific example of the second embodiment will be described with reference to the block diagram shown in FIG.

In this specific example, mainly, processing when the access means 40 receives a data write request from the external device 20, processing when the access means 40 receives a data read request from the external device 20, and update means 70 The update processing to be performed will be described.

First, the processing when the access means 40 receives a data write request from the external device 20 will be described using a specific example.

Upon receiving a data write request from the external device 20 , the access means 40 writes the data to the storage medium 30 and writes position information indicating the position where the data was written to the write metadata 50 .

FIG. 6 shows a specific example of the write metadata 50 in which the location information is written by the access means 40 .

Write metadata 50 includes logical addresses 51 and physical addresses 52 .

The logical address 51 is information indicating the position where the external device 20 has issued a write request.

The physical address 52 is information indicating the storage location of data stored in the storage medium 30 . Note that the logical address 51 and the physical address 52 may express position information using addresses and data amounts. For example, the logical address 51 may be represented by information of YY bytes from address "AA", and the physical address 52 corresponding to the information may be represented by information of "YY bytes from Disc 1, address 2". You may express the information of a position. Note that any method may be used for the logical address 51 and the physical address 52 as long as they represent position information. Further, the position information may be information on the physical address 52, or information on the physical address 52 and the amount of data.

Specifically, when the access means 40 receives a data write request to write XX bytes from the address “ZZ” from the external device 20 and writes XX bytes to “Disc 3, address 1” of the storage medium 30, the logical address 51 is writes "ZZ" to physical address 52, and writes "Disc3, address 1" to physical address 52.

Next, the processing when the access means 40 receives a data read request from the external device 20 will be described using a specific example.

When receiving a data read request from the external device 20, the access means 40 accesses the read metadata 60, refers to the position information included in the read metadata 60, and stores the data corresponding to the read request on the storage medium. Identify the location at 30 .

FIG. 7 shows a specific example of read metadata 60. As shown in FIG.

Read metadata 60 includes logical addresses 61 and physical addresses 62 .

The logical address 61 is information indicating an address from which the external device 20 makes a read request.

The physical address 62 is address information indicating the storage position of data stored in the storage medium 30 . Note that the logical address 61 and the physical address 62 may also express position information using addresses and data amounts in the same manner as the logical address 51 and the physical address 52 .

Specifically, when the access means 40 receives a data read request to read YY bytes from the address “AA” from the external device 20 , the access means 40 refers to the logical address 61 and physical address 62 of the read metadata 60 . As a result of referring to the logical address 61 and the physical address 62, the access means 40 identifies that the data corresponding to the address "AA" is stored in the storage medium 30 at the location "Disc1, Address 2". The access means 40 reads YY bytes from “Disc 1, Address 2” and transmits the data to the external device 20 .

Next, the updating process performed by the updating means 70 will be described using a specific example.

The updating means 70 accesses the write metadata 50 and the read metadata 60 and updates the position information included in the read metadata 60 . In this specific example, as an example of update processing, processing for adding position information newly written in the write metadata 50 since the previous update to the read metadata 60 as a difference will be described.

FIG. 8 shows a conceptual diagram of update processing. The conceptual diagram of the update process shown in FIG. 8 shows a conceptual diagram of write metadata 50 in the upper half, and a conceptual diagram of read metadata 60 in the lower half. Also, in the conceptual diagram shown in FIG. 8, the update process will be described using three steps. In the conceptual diagram shown in FIG. 8, step 1 described in the upper half and step 1 described in the lower half indicate the same time.

Step 1 indicates that the conceptual diagram of write metadata 50 and the conceptual diagram of read metadata 60 contain the same location information.

Here, it is assumed that the access means 40 writes new position information to the write metadata 50 in step 2 . The new location information is called new location information 80 . Referring to step 2, it can be seen that new location information 80 has been added to the conceptual diagram of the metadata for writing 50 . At the time of step 2, the new position information 80 has not been added to the reading metadata 60. FIG. Therefore, at the time of step 2, even if the external device 20 requests to read data corresponding to the new position information 80, the data corresponding to the new position information 80 cannot be read. It should be noted that even at the time of step 2, it is possible to read the data before the new position information 80 .

In step 3, a specific example is shown in which the update means 70 performs update processing and new position information 80 is added to the read metadata 60. FIG. The conceptual diagram of write metadata 50 and the conceptual diagram of read metadata 60 shown in step 3 indicate that they contain the same location information.

The access means 40 may refer to the new position information 80 when searching for desired position information, and may refer to position information other than the new position information 80 when the desired position information is not found. .

As a result, the present invention according to the second embodiment can efficiently access metadata. The reason for this is that managing the write metadata 50 and the read metadata 60 separately reduces the possibility of write conflict occurring in the read metadata 60 .

In addition, according to the present invention according to the second embodiment, the update means 70 performs update processing to update the position information included in the readout metadata 60, so that the external device 20 is newly stored in the storage medium 30. Data can be read. Note that the position information included in the read metadata 60 indicates the position of data that has already been written to the storage medium 30 due to its nature. Therefore, when data is read using the position information included in the read metadata 60, the data being written to the storage medium 30 is not read. That is, even if the present invention is applied to a technical field in which real-time data is accumulated, it is possible to prevent reading of data whose value changes in real-time due to writing or the like. This configuration is particularly effective in techniques for analyzing data accumulated in the past while accumulating data such as weather forecasts, analysis of past stock price trends, analysis of popular products, and the like.

Furthermore, since the present invention according to the second embodiment includes a plurality of access means 40 and read metadata 60, it is possible to efficiently respond to read requests from the external device 20. FIG.

Note that when a plurality of access means 40 simultaneously read out position information from one read metadata 60, a bus (means for accessing metadata) possessed by a memory or the like for storing the metadata is used. bandwidth is squeezed, and the reading performance of the metadata may be degraded. However, since the present invention according to the second embodiment includes a plurality of reading metadata 60, it is possible to prevent deterioration of reading performance of the metadata.

Although the write metadata 50 in this specific example includes the same position information as the read metadata 60, the present invention is not limited to this. For example, the updating unit 70 may add the position information included in the write metadata 50 to the read metadata 60 and then delete the added position information from the write metadata 50 . By doing so, the capacity of the write metadata 50 can be reduced.

In this embodiment, an embodiment in which metadata is included in the storage device 10 has been described, but the present invention is not limited to this. For example, an information processing system in which a server containing metadata 50 for writing and a plurality of servers containing metadata 60 for reading are connected to a single storage medium may be used. In this case, each server is connected by a network, and the storage medium is connected by a high-speed interface such as PCIe (Peripheral Component Interconnect-Express).

Note that the storage device 10 may further include a cache. For example, when a read request is received from the external device 20 , the target data may be transmitted from the storage medium 30 to the cache, and the target data may be transmitted from the cache to the access means 40 .
[program]
A program in the present invention is a program that causes a computer to execute the processing of the present invention. The present invention can be implemented by installing and executing this program on a computer.

A computer that implements the present invention by executing the program of the present invention will now be described with reference to FIG.

FIG. 11 is a block diagram showing an example of a computer that implements the present invention.

As shown in FIG. 11 , computer 110 includes CPU 111 , main memory 112 , storage device 113 , input interface 114 , display controller 115 , data reader/writer 116 and communication interface 117 . These units are connected to each other via a bus 121 so as to be able to communicate with each other.

The CPU 111 expands the programs (codes) of the present invention stored in the storage device 113 into the main memory 112 and executes them in a predetermined order to perform various calculations. The main memory 112 is typically a volatile storage device such as a DRAM (Dynamic Random Access Memory). Also, the program according to the present invention is provided in a state stored in a computer-readable recording medium 120 . It should be noted that the program in the present invention may be distributed on the Internet connected via the communication interface 117 .

The storage device 113 may be a hard disk drive or a semiconductor storage device such as a flash memory. Input interface 114 mediates data transmission between CPU 111 and input device 118 . The input device 118 includes, for example, a keyboard, a mouse, and a touch panel. The display controller 115 is connected to the display device 119 and controls display on the display device 119 .

Data reader/writer 116 mediates data transmission between CPU 111 and recording medium 120 , reads programs from recording medium 120 , and writes processing results in computer 110 to recording medium 120 . Communication interface 117 mediates data transmission between CPU 111 and other computers.

Specific examples of the recording medium 120 include general-purpose semiconductor storage devices such as CF (Compact Flash (registered trademark)) and SD (Secure Digital), or magnetic storage media such as flexible disks. . Furthermore, a specific example of the recording medium 120 includes an optical storage medium such as a CD-ROM (Compact Disk Read Only Memory).
<First modification>
A first modification of the second embodiment of the present invention will be described with reference to the drawings. Note that the same description as in the second embodiment will be omitted.

FIG. 9 is a diagram showing the configuration of the storage device 11 in the first modified example.

As shown in FIG. 9, the storage device 11 in the first modified example includes one piece of read metadata 60 unlike the second embodiment.

Upon receiving a read request from the external device 20 , the access means 40 refers to the position information included in the read metadata 60 and reads data corresponding to the read request from the storage medium 30 .

When data is written to metadata, a write conflict occurs, so exclusive control, etc. is performed, and the metadata cannot be accessed efficiently. , no conflict occurs, so no exclusive control is performed. Therefore, the storage device 11 in the first modified example can efficiently access the metadata even if it is configured to include one piece of read metadata 60 .

Note that when a plurality of access means 40 simultaneously read out position information from one read-out metadata 60, the bandwidth of the bus (means for accessing metadata) possessed by the metadata is squeezed, There is a possibility that the reading performance of the metadata may be degraded. Therefore, in the present invention, it is desirable to set the number of reading metadata 60 within a range in which the reading performance of metadata does not deteriorate.
<Second modification>
A second modification of the second embodiment of the present invention will be described with reference to the drawings. Note that the same description as in the second embodiment will be omitted.

FIG. 10 is a diagram showing the configuration of the storage device 12 in the second modified example.

As shown in FIG. 10 , the storage device 12 in the second modification includes write access means 200 , read access means 220 and read access means 240 instead of the access means 40 . Also, the storage device 12 in the second modified example includes write metadata 210 instead of the write metadata 50 . Furthermore, the storage device 12 in the second modification includes read metadata 230 and read metadata 250 instead of the read metadata 60 .

Upon receiving a write request from the external device 20 , the write access means 200 writes data to the storage medium 30 and writes position information indicating the position where the data was written to the write metadata 210 .

Upon receiving a read request from the external device 20 , the read access means 220 refers to the position information included in the read metadata 230 and reads data corresponding to the read request from the storage medium 30 .

Upon receiving a read request from the external device 20 , the read access means 240 refers to the position information included in the read metadata 250 and reads data corresponding to the read request from the storage medium 30 .

Thus, in the second modification, means for accessing write metadata and means for accessing read metadata are configured separately. Also, the access means and the metadata are each configured as a set according to the application. Specifically, in the second modification, a set of write access means 200 and write metadata 210, a set of read access means 220 and read metadata 230, a read access means 240 and read metadata It consists of three sets of data 250 . In the second modified example, the storage device 12 has been described as including three sets, but the present application is not limited to this.

In this way, the access means and the metadata are configured as a set according to the application, so the storage device 12 in the second modification can limit the access means for accessing the metadata to one. can. In other words, the storage device 12 in the second modification can prevent multiple access means from accessing one metadata by limiting the access means for accessing metadata to one.

Although the embodiments for carrying out the present invention have been described so far, the present invention is not limited to the above-described embodiments. For example, the order of processing in the flowcharts described in this specification is merely an example, and can be changed within a range that does not contradict when implementing the present invention. Moreover, the configuration described in this specification is merely an example, and it is possible to change the configuration within a range that is not inconsistent when implementing the present invention. That is, the present invention can apply various aspects that can be understood by those skilled in the art within a range that is not inconsistent when implementing the present invention, and modifications of the above embodiments, combinations thereof, etc. included in the technical scope of
[Appendix]
Some or all of the above embodiments may also be described as the following appendices. The outline of the configuration of the present invention will be described below. However, the present invention is not limited to the following configurations.
(Appendix 1)
a storage medium for storing data;
a plurality of access means for performing a process of writing data to the storage medium and a process of reading data from the storage medium;
a first storage means for storing first metadata including position information indicating positions where the plurality of access means have written data to the storage medium;
a second storage means for storing second metadata including position information indicating the storage position of the data in the storage medium;
the plurality of access means reads data from the storage medium using the second metadata;
storage.
(Appendix 2)
Of the plurality of access means, an access means for writing data to the storage medium stores position information indicating a position where the data is written to the storage medium as first metadata when the data is written to the storage medium. write to
Storage as described in Appendix 1.
(Appendix 3)
Of the plurality of access means, the access means for writing data to the storage medium writes the data to a position different from a position where the data is already stored in the storage medium.
The storage according to Appendix 1 or 2.
(Appendix 4)
further comprising updating means for updating location information contained in said second metadata using location information in said first metadata;
The storage according to any one of Appendices 1 to 3.
(Appendix 5)
The updating means copies location information in the first metadata to location information included in the second metadata.
Storage as described in Appendix 4.
(Appendix 6)
The updating means adds position information newly written in the first metadata since the previous update to the second metadata as a difference.
Storage as described in Appendix 4.
(Appendix 7)
The updating means deletes the newly written position information from the first metadata when the newly written position information is added to the second metadata and the third metadata. ,
Storage as described in Appendix 6.
(Appendix 8)
further comprising third storage means for storing third metadata including position information indicating the storage position of the data in the storage medium;
The plurality of access means reads data from the storage medium using the second metadata or the third metadata.
8. The storage according to any one of Appendices 1-7.
(Appendix 9)
The storage according to any one of Appendices 1 to 8;
one or more computers;
a first access means among the plurality of access means writes data to the storage medium upon receiving a data write request from the computer;
a second access means among the plurality of access means writes data to the storage medium upon receiving a data read request from the computer;
Information processing system.
(Appendix 10)
a storage medium for storing data;
a first server that writes data to the storage medium;
a second server that reads data from the storage medium;
The first server stores first metadata including location information indicating a location where the first server has written data to the storage medium;
The second server stores second metadata including position information indicating a storage position of data in the storage medium, and reads data from the storage medium using the second metadata.
Information processing system.
(Appendix 11)
The updating means deletes the newly written position information from the first metadata when the newly written position information is added to the second metadata and the third metadata. ,
Storage as described in Appendix 7.
(Appendix 12)
a storage medium for storing data;
a first access means for writing data to the storage medium;
a second access means for reading data from the storage medium;
a first storage means for storing first metadata including position information indicating a position where the first access means has written data to the storage medium;
a second storage means for storing second metadata including position information indicating the storage position of the data in the storage medium;
the second access means reads data from the storage medium using the second metadata;
storage.

1 storage 2 storage medium 3 first access means 4 second access means 5 first storage means 6 second storage means 10 storage device 20 external device 30 storage medium 40 access means 50 metadata for writing 51 logical address 52 Physical Address 60 Read Metadata 61 Logical Address 62 Physical Address 70 Updating Means 80 New Location Information 110 Computer 111 CPU
112 Main memory 113 Storage device 114 Input interface 115 Display controller 116 Data reader/writer 117 Communication interface 118 Input device 119 Display device 120 Recording medium 200 Access means for writing 210 Metadata for writing 220 Access means for reading 230 Metadata for reading 240 read access means 250 read metadata

Claims (10)

a storage medium for storing data;
a plurality of access means for performing a process of writing data to the storage medium and a process of reading data from the storage medium;
a first storage means for storing first metadata including position information indicating positions where the plurality of access means have written data to the storage medium;
a second storage means for storing second metadata including position information indicating a data storage position in the storage medium;
updating means for updating the location information included in the second metadata using the location information in the first metadata;
Of the plurality of access means, when data is written to the storage medium, the access means for writing data to the storage medium transmits position information indicating the position where the data was written to the storage medium to the first meta. write new data
The updating means updates the location information included in the second metadata so that the newly written location information is included in the first metadata,
When reading predetermined data from the storage medium, the plurality of access means searches the second metadata for position information of the predetermined data, and identifies the position information of the predetermined data. , using the identified position information to read the predetermined data from the storage medium;
The plurality of access means refer to the newly written position information in the second metadata when retrieving the position information of the predetermined data in the second metadata. do,
storage. Of the plurality of access means, the access means for writing data to the storage medium writes the data to a position different from a position where the data is already stored in the storage medium.
The storage of Claim 1. The updating means copies location information in the first metadata to location information included in the second metadata.
3. Storage according to claim 1 or 2. The update means adds the newly written position information from the previous update to the second metadata as a difference.
3. Storage according to claim 1 or 2. The updating means deletes the newly written location information from the first metadata when the newly written location information is added to the second metadata.
5. Storage according to claim 4. further comprising third storage means for storing third metadata including position information indicating the storage position of the data in the storage medium;
the plurality of access means read data from the storage medium using the second metadata or the third metadata;
Storage according to any one of claims 1 to 5. The update means adds the newly written position information from the previous update to the second metadata and the third metadata as a difference.
7. Storage according to claim 6. The updating means deletes the newly written position information from the first metadata when the newly written position information is added to the second metadata and the third metadata. ,
8. Storage according to claim 7. A storage according to any one of claims 1 to 8;
one or more computers;
a first access means among the plurality of access means, upon receiving a data write request from the computer, writes data to the storage medium;
a second access means among the plurality of access means writes data to the storage medium upon receiving a data read request from the computer;
Information processing system. a storage medium for storing data;
a first server that writes data to the storage medium;
a second server that reads data from the storage medium;
updating means;
The first server stores first metadata including location information indicating a location where the first server has written data to the storage medium;
The second server stores second metadata including position information indicating a data storage position in the storage medium,
The updating means updates the location information included in the second metadata so that the newly written location information is included in the first metadata,
When the second server reads the predetermined data from the storage medium, the second server searches the second metadata for the position information of the predetermined data, and specifies the position information of the predetermined data. , using the identified position information to read the predetermined data from the storage medium;
The second server refers to the newly written position information in the second metadata when retrieving the position information of the predetermined data in the second metadata. do,
Information processing system.

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