WO2022172548A1

WO2022172548A1 - Information processing device, information processing method, and information processing program

Info

Publication number: WO2022172548A1
Application number: PCT/JP2021/042669
Authority: WO
Inventors: 豊大石; 輝江渡邊; 理貴近藤; 優子宇野; 美咲大塚
Original assignee: 富士フイルム株式会社
Priority date: 2021-02-15
Filing date: 2021-11-19
Publication date: 2022-08-18
Also published as: JPWO2022172548A1

Abstract

This information processing device determines, on the basis of error rates of a plurality of respective partial areas into which a magnetic tape is divided, the partial areas of recording destinations of a plurality of respective types of data.

Description

Information processing device, information processing method, and information processing program

The present disclosure relates to an information processing device, an information processing method, and an information processing program.

Japanese Patent Application Laid-Open No. 2007-080459 discloses a technique of holding an error rate for each partial area into which a magnetic tape is divided. This technique determines the position of data to be rewritten based on this error rate.

By the way, recent magnetic tapes can be divided into, for example, a first partition in which data is recorded and a second partition in which metadata about data is recorded.

When reading specific data out of a large number of data recorded in the first partition, first read the metadata group recorded in the second partition. Next, based on the read metadata group, the recording position of the data to be read is specified, and the data is read from the first partition. Therefore, if errors occur frequently when reading the metadata recorded in the second partition, the data reading efficiency will also decrease.

Also, for example, it is conceivable to record in the first partition with metadata added to the data. In this case, metadata is redundantly recorded in the first and second partitions, but data is recorded only in the first partition. Therefore, in this case, and when data reliability is prioritized over the frequency of errors in reading metadata, the first partition is preferably more reliable than the second partition.

As described above, when multiple types of data, such as data and metadata, are recorded in divided partial areas of a magnetic tape, it is preferable to determine an appropriate partial area for recording. However, the technique described in Japanese Patent Application Laid-Open No. 2007-080459 does not consider in which partial area of the magnetic tape the multiple types of data are to be recorded.

The present disclosure has been made in view of the above circumstances, and is an information processing method capable of appropriately determining a partial area for recording each of a plurality of types of data from among a plurality of partial areas into which a magnetic tape is divided. An object is to provide an apparatus, an information processing method, and an information processing program.

An information processing apparatus according to the present disclosure is an information processing apparatus that includes at least one processor, and the processor determines the recording destinations of the plurality of types of data based on the error rates of the plurality of partial areas into which the magnetic tape is divided. Determine the subregion of .

Further, in the information processing apparatus of the present disclosure, the plurality of types of data include data and metadata about the data, and the processor selects a partial area whose error rate is equal to or lower than a predetermined threshold as the first data recording area. It may be determined as an area to be used as the second partition among the partitions and the second partition in which the metadata is recorded.

Further, in the information processing apparatus of the present disclosure, the plurality of types of data include data and metadata related to the data, and the processor records a predetermined number of partial areas in descending order of error rate. Of the first partition and the second partition in which the metadata is recorded, the area to be used as the second partition may be determined.

Further, in the information processing apparatus of the present disclosure, each of the plurality of first partial regions obtained by dividing the magnetic tape along lines along the longitudinal direction of the magnetic tape is divided by lines along the width direction of the magnetic tape. and the error rate may be the error rate of each of the plurality of first partial regions derived based on the error rate of each of the plurality of partial regions.

Further, in the information processing apparatus of the present disclosure, each of the plurality of first partial regions obtained by dividing the magnetic tape along lines along the longitudinal direction of the magnetic tape is divided by lines along the width direction of the magnetic tape. A plurality of second partial regions obtained by dividing the magnetic tape by lines along the width direction of the magnetic tape, wherein the error rate is derived based on the error rate of each of the plurality of partial regions. It may be the error rate of each of the three partial areas.

Further, in the information processing method of the present disclosure, a processor provided in an information processing apparatus performs a process of determining a partial area for recording each of a plurality of types of data based on the error rate of each of a plurality of partial areas into which a magnetic tape is divided. is what is executed.

Further, the information processing program of the present disclosure is a processor provided in an information processing apparatus that determines a partial area for recording each of a plurality of types of data based on the error rate of each of a plurality of partial areas into which a magnetic tape is divided. to run

According to the present disclosure, it is possible to appropriately determine the partial area of the recording destination for each of the plurality of types of data from among the plurality of partial areas into which the magnetic tape is divided.

1 is a block diagram showing an example of the configuration of an information processing system; FIG. FIG. 4 is a diagram for explaining an object; FIG. It is a schematic diagram which shows an example of a magnetic tape. It is a block diagram which shows an example of the hardware constitutions of an information processing apparatus. FIG. 4 is a diagram for explaining error rate information; FIG. 1 is a block diagram showing an example of a functional configuration of an information processing device; FIG. FIG. 4 is a diagram for explaining a method of deriving an error rate of a partial area; It is a figure for demonstrating the determination result by a determination part. 5 is a flowchart showing an example of magnetic tape reuse processing; It is a figure for demonstrating the derivation|leading-out method of the error rate of the partial area|region which concerns on a modification. It is a figure for demonstrating the determination result by the determination part which concerns on a modification.

Embodiments for implementing the technology of the present disclosure will be described in detail below with reference to the drawings.

First, the configuration of an information processing system 10 according to the present embodiment will be described with reference to FIG. As shown in FIG. 1, the information processing system 10 includes an information processing device 12 and a tape library 14 . Examples of the information processing device 12 include a server computer and the like.

The tape library 14 comprises a plurality of slots (not shown) and a plurality of tape drives 18, each slot storing a magnetic tape T as an example of a recording medium. Each tape drive 18 is connected to the information processing device 12 . The tape drive 18 writes data to or reads data from the magnetic tape T under the control of the information processing device 12 . An example of the magnetic tape T is an LTO (Linear Tape-Open) tape.

When the information processing device 12 writes data to or reads data from the magnetic tape T, the magnetic tape T to be written or read is loaded from the slot into the predetermined tape drive 18 . After data has been written or read from the magnetic tape T loaded in the tape drive 18, the magnetic tape T is unloaded from the tape drive 18 to the slot in which it was originally stored.

In this embodiment, as an example, as shown in FIG. 2, a unit handling data to be recorded on the magnetic tape T includes data to be stored by the user, such as document data and image data, and metadata related to the data. A form example to which an object is applied will be described. In the example of FIG. 2, the metadata is written as "meta". A storage system that handles this object is called an object storage system. The metadata includes, for example, object identification information such as object keys, object names, data sizes, and attribute information such as time stamps. The recording order of the data and the metadata when recording the object on the magnetic tape T is not particularly limited, and may be the order of the metadata and the data, or the order of the data and the metadata.

Next, the configuration of the magnetic tape T according to this embodiment will be described with reference to FIG. As shown in FIG. 3, when the magnetic tape T is formatted, it is divided into two partitions, a reference partition RP in which metadata is recorded and a data partition DP in which objects are recorded. The data partition DP is an example of a first partition in which data is recorded, and the reference partition RP is an example of a second partition in which metadata is recorded. Metadata and objects are examples of multiple types of data.

Next, the hardware configuration of the information processing device 12 according to this embodiment will be described with reference to FIG. As shown in FIG. 4, the information processing device 12 includes a CPU (Central Processing Unit) 20, a memory 21 as a temporary storage area, and a non-volatile storage section 22. FIG. The information processing device 12 also includes a display 23 such as a liquid crystal display, an input device 24 such as a keyboard and a mouse, a network I/F (InterFace) 25 connected to a network, and an external I/F to which each tape drive 18 is connected. Including F26. CPU 20 , memory 21 , storage unit 22 , display 23 , input device 24 , network I/F 25 and external I/F 26 are connected to bus 27 .

The storage unit 22 is implemented by a HDD (Hard Disk Drive), SSD (Solid State Drive), flash memory, or the like. An information processing program 30 is stored in the storage unit 22 as a storage medium. The CPU 20 reads out the information processing program 30 from the storage unit 22 , expands it in the memory 21 , and executes the expanded information processing program 30 .

In addition, error rate information 32 regarding the error rate of the magnetic tape T is stored in the storage unit 22 . The error rate information 32 will be described with reference to FIG. The error rate information 32 includes a plurality of first partial regions P1 obtained by dividing the magnetic tape T by straight lines along the longitudinal direction of the magnetic tape T (hereinafter referred to as "tape longitudinal direction"). The error rate of each of the second partial regions P2 divided by straight lines along the direction (hereinafter referred to as "tape width direction") is included. The partial area P1 is, for example, one wrap. Note that the partial region P1 may be a plurality of wraps. The numerical values in FIG. 5 represent the error rate of each partial area P2.

The error rate here means the rate at which read errors occurred in each partial area P2 when data recorded on the magnetic tape T in the past was read. This read error may include not only the case where the data could not be read, but also the case where an error occurred during reading but the data could be read by error correction using an error correction code.

By the way, in this embodiment, the magnetic tape T is reused. Reuse of the magnetic tape T means, for example, initializing the magnetic tape T on which the retention period of all recorded data has passed.

In addition, since it is difficult to delete only part of the data recorded in the middle of the magnetic tape T, data deleted by the user is added with, for example, a deletion flag indicating that it has been deleted. is logically deleted by All the data recorded on the magnetic tape T on which such logically deleted data is recorded are read, the magnetic tape T is initialized, and only the data to which the deletion flag is not assigned among the read data. is recorded on the magnetic tape T. As a result, since the logically deleted data is also physically deleted from the magnetic tape T, the free space of the magnetic tape T increases. The process of increasing the free space in this way also corresponds to the reuse of the magnetic tape T. FIG.

The information processing device 12 according to the present embodiment has a function of determining a partial area where data is to be recorded when the magnetic tape T is reused.

Next, with reference to FIG. 6, the functional configuration of the information processing device 12 according to this embodiment will be described. As shown in FIG. 6, the information processing device 12 includes an acquisition unit 40, a derivation unit 42, a determination unit 44, and a control unit 46. FIG. By executing the information processing program 30 , the CPU 20 functions as an acquisition unit 40 , a derivation unit 42 , a determination unit 44 and a control unit 46 .

The acquisition unit 40 acquires the error rate of each of the plurality of partial regions P2 included in the error rate information 32 stored in the storage unit 22. The derivation unit 42 derives the error rate of each of the plurality of partial regions P1 based on the error rate of each of the plurality of partial regions P2 acquired by the acquisition unit 40 . Specifically, as shown in FIG. 7 as an example, the deriving unit 42 derives the average value of the error rates of all the partial areas P2 included in the partial area P1 for each partial area P1, thereby Derive the error rate of P1.

The determination unit 44 determines the partial area P1 whose error rate derived by the derivation unit 42 is equal to or less than a predetermined threshold TH as the area to be used as the reference partition RP. Further, the determination unit 44 determines the partial area P1 in which the error rate derived by the derivation unit 42 exceeds the threshold TH as the area to be used as the data partition DP. As an example, when the error rate is the value shown in FIG. 7 and the threshold TH is 0.5, the area to be used as the reference partition RP and the area to be used as the data partition DP are determined as shown in FIG. be done.

Note that the determination unit 44 may determine a predetermined number K of partial regions P1 in descending order of the error rate derived by the derivation unit 42 as the regions to be used as the reference partition RP. In this case, the determining unit 44 determines partial areas P1 other than the number K of partial areas P1 as areas to be used as the data partition DP. As an example, when the error rate is the value shown in FIG. 7 and the number K is 1, the area to be used as the reference partition RP and the area to be used as the data partition DP are determined as shown in FIG. . The number K in this case is set, for example, so that the capacity ratio of the data partition DP and the reference partition RP is the average capacity ratio of objects and metadata stored in the information processing system 10 .

The control unit 46 performs control for reusing the magnetic tape T according to the determination result of the determination unit 44 . Specifically, for example, in the case of initializing a magnetic tape T on which the retention period of all recorded data has passed, the control unit 46 provides identification information of the magnetic tape T to be reused and an initialization instruction. to the tape drive 18. The tape drive 18 initializes the magnetic tape T indicated by the identification information sent from the information processing device 12 . Further, the control unit 46 stores information indicating that the partial area P1 determined by the determination unit 44 as the area to be used as the reference partition RP is the reference partition RP in the storage area for storing the management information of the magnetic tape T. to control. Further, the control unit 46 stores information indicating that the partial area P1 determined by the determination unit 44 as the area to be used as the data partition DP is the data partition DP in the storage area for storing the management information of the magnetic tape T. to control. Examples of the storage area for storing the management information of the magnetic tape T include a cartridge memory provided in the magnetic tape cartridge containing the magnetic tape T, a partial area for recording the management information on the magnetic tape T, and a storage area of the storage unit 22. At least one is mentioned.

Also, for example, when performing processing to increase the free space of the magnetic tape T, the control unit 46 performs the following control before the initialization of the magnetic tape T described above. In this case, the control unit 46 performs control to read the metadata recorded in the reference partition RP and the object recorded in the data partition DP of the magnetic tape T to be reused. Also, in this case, the control unit 46 performs control to store the read metadata and object in the storage unit 22 . At the time of this control, the control unit 46 discards the metadata and objects to which the deletion flag is added as being excluded from being stored in the storage unit 22 .

When performing processing to increase the free space of the magnetic tape T, the control unit 46 further performs the following control after the initialization of the magnetic tape T described above. In this case, the control unit 46 records the metadata stored in the storage unit 22 before the initialization of the magnetic tape T in the reference partition RP of the magnetic tape T after initialization, and records the object on the magnetic tape after initialization. It controls recording in the data partition DP of T.

Next, the operation of the information processing device 12 according to this embodiment will be described with reference to FIG. The CPU 20 executes the information processing program 30 to execute the magnetic tape reuse process shown in FIG. The magnetic tape reuse processing shown in FIG. 9 is executed, for example, when an execution instruction is input by the user. At this time, for example, the identification information of the magnetic tape T to be reused is input by the user.

At step S10 in FIG. 9, the acquisition unit 40 acquires the error rate of each of the plurality of partial regions P2 included in the error rate information 32 stored in the storage unit 22. In step S12, the derivation unit 42 derives the error rate of each of the partial areas P1 based on the error rate of each of the partial areas P2 obtained in step S10, as described above.

In step S14, the determining unit 44 determines the partial area P1 whose error rate derived in step S12 is equal to or lower than the threshold TH as the area to be used as the reference partition RP. Further, the determination unit 44 determines the partial area P1 in which the error rate derived in step S12 exceeds the threshold TH as the area to be used as the data partition DP.

At step S16, the control unit 46 performs control to reuse the magnetic tape T according to the determination result at step S14, as described above. When the process of step S16 ends, the magnetic tape reuse process ends.

As described above, according to the present embodiment, it is possible to appropriately determine the recording destination partial areas for each of the plurality of types of data from among the plurality of partial areas into which the magnetic tape T is divided.

In the above embodiment, the deriving unit 42 may derive the error rate of each of the plurality of partial regions P3 obtained by dividing the magnetic tape T by straight lines along the tape width direction. In this case, the derivation unit 42 derives the error rate of each of the plurality of partial regions P3 based on the error rate of each of the plurality of partial regions P2 acquired by the acquisition unit 40 . Specifically, as shown in FIG. 10 as an example, the deriving unit 42 derives the average value of the error rates of all the partial regions P2 included in the partial region P3 for each partial region P3. Derive the error rate of P3.

In this case, the determination unit 44 determines the partial area P3 whose error rate derived by the derivation unit 42 is equal to or less than the threshold TH as the area to be used as the reference partition RP. Further, the determination unit 44 determines the partial area P3 in which the error rate derived by the derivation unit 42 exceeds the threshold TH as the area to be used as the data partition DP. As an example, when the error rate is the value shown in FIG. 10 and the threshold TH is 0.7, the area to be used as the reference partition RP and the area to be used as the data partition DP are determined as shown in FIG. be done.

Also, in this case, the determination unit 44 may determine a predetermined number K of partial regions P3 in descending order of the error rate derived by the derivation unit 42 as regions to be used as the reference partition RP. In this case, the determining unit 44 determines partial areas P3 other than the number K of partial areas P3 as areas to be used as data partitions DP. As an example, when the error rate is the value shown in FIG. 10 and the number K is 1, the area to be used as the reference partition RP and the area to be used as the data partition DP are determined as shown in FIG. . The number K in this case is set, for example, so that the capacity ratio of the data partition DP and the reference partition RP is the average capacity ratio of objects and metadata stored in the information processing system 10 .

Also, in the above embodiment, some users may want to increase the reliability of data recorded only in the data partition DP rather than metadata recorded in both the reference partition RP and the data partition DP. In this case, the determination unit 44 may determine the partial area P1 whose error rate derived by the derivation unit 42 is equal to or less than the threshold TH as the area to be used as the data partition DP. Also, in this case, the determining unit 44 may determine the partial area P1 in which the error rate derived by the deriving unit 42 exceeds the threshold TH as the area to be used as the reference partition RP.

In this case, the determination unit 44 may determine a predetermined number K of partial regions P1 in descending order of the error rate derived by the derivation unit 42 as regions to be used as the reference partition RP. In this case, the determining unit 44 may determine partial areas P1 other than the number K of partial areas P1 as areas to be used as the data partition DP.

Also, the partial areas P1, P2, and P3 may be equally divided areas or may not be equally divided areas.

Further, in the above embodiment, for example, the hardware structure of the processing unit (processing unit) that executes various processes such as the acquisition unit 40, the derivation unit 42, the determination unit 44, and the control unit 46 is shown below. Various processors can be used. As described above, the various processors include, in addition to the CPU, which is a general-purpose processor that executes software (programs) and functions as various processing units, circuits such as FPGAs (Field Programmable Gate Arrays), etc. Programmable Logic Device (PLD) which is a processor whose configuration can be changed, ASIC (Application Specific Integrated Circuit) etc. Circuits, etc. are included.

One processing unit may be composed of one of these various processors, or a combination of two or more processors of the same type or different types (for example, a combination of multiple FPGAs, a combination of a CPU and an FPGA). combination). Also, a plurality of processing units may be configured by one processor.

As an example of configuring a plurality of processing units with a single processor, first, as represented by computers such as clients and servers, a single processor is configured by combining one or more CPUs and software. There is a form in which a processor functions as multiple processing units. Second, as typified by System on Chip (SoC), etc., there is a form of using a processor that realizes the functions of the entire system including multiple processing units with a single IC (Integrated Circuit) chip. be. In this way, the various processing units are configured using one or more of the above various processors as a hardware structure.

Furthermore, as the hardware structure of these various processors, more specifically, an electric circuit combining circuit elements such as semiconductor elements can be used.

Also, in the above embodiment, the information processing program 30 has been pre-stored (installed) in the storage unit 22, but the present invention is not limited to this. The information processing program 30 is provided in a form recorded on a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), and a USB (Universal Serial Bus) memory. good too. Further, the information processing program 30 may be downloaded from an external device via a network.

The disclosure of Japanese Patent Application No. 2021-021958 filed on February 15, 2021 is incorporated herein by reference in its entirety. In addition, all publications, patent applications, and technical standards mentioned herein are to the same extent as if each individual publication, patent application, or technical standard were specifically and individually noted to be incorporated by reference. , incorporated herein by reference.

Claims

An information processing device comprising at least one processor,
The processor
1. An information processing device that determines a partial area for recording each of a plurality of types of data based on the error rate of each of a plurality of partial areas into which a magnetic tape is divided.
The plurality of types of data includes data and metadata about the data,
The processor
A partial area whose error rate is equal to or lower than a predetermined threshold is determined as an area to be used as the second partition, out of the first partition in which the data is recorded and the second partition in which the metadata is recorded. The information processing apparatus according to claim 1.
The plurality of types of data includes data and metadata about the data,
The processor
A predetermined number of partial areas in descending order of error rate are used as the second partition out of the first partition in which the data is recorded and the second partition in which the metadata is recorded. The information processing apparatus according to claim 1, wherein the region is determined.
Each of the plurality of partial areas is a plurality of first partial areas obtained by dividing the magnetic tape along lines along the longitudinal direction of the magnetic tape, and second partial areas obtained by dividing each of the plurality of partial areas along lines along the width direction of the magnetic tape. is a subregion,
4. The information processing apparatus according to claim 2, wherein the error rate is the error rate of each of the plurality of first partial areas derived based on the error rate of each of the plurality of partial areas.
Each of the plurality of partial areas is a plurality of first partial areas obtained by dividing the magnetic tape along lines along the longitudinal direction of the magnetic tape, and second partial areas obtained by dividing each of the plurality of partial areas along lines along the width direction of the magnetic tape. is a subregion,
The error rate is the error rate of each of a plurality of third partial regions obtained by dividing the magnetic tape along lines along the width direction of the magnetic tape, which are derived based on the error rates of the plurality of partial regions. The information processing apparatus according to claim 2 or 3.
An information processing method in which a processor included in an information processing apparatus executes a process of determining a partial area where each of a plurality of types of data is to be recorded based on the error rate of each of a plurality of partial areas into which a magnetic tape is divided.
An information processing program for causing a processor included in an information processing apparatus to execute a process of determining a partial area for recording each of a plurality of types of data based on error rates of each of a plurality of partial areas into which a magnetic tape is divided.