JP2002091707A - File information managing method in storage medium library system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the data read/write processing efficiency in a library system, which uses a removable storage medium. SOLUTION: When a storage medium is housed in a drive, a prescribed information is read out of the storage medium and this information is stored in a data storage device. In the case of data read/write, the information stored on this data storage device is accessed and this information is updated. When taking the storage medium out of the drive, the information stored on the storage device are totally written on the storage medium. Thus, the information stored in the data storage medium is accessed and updated without directly performing data access to the storage medium. Thus, by suppressing the data access to the storage medium to the minimum, the working efficiency of the storage medium library system can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CD-ROM,
In a storage medium library system for storing and driving a disk-shaped storage medium such as a VD or another type of storage medium, the present invention relates to a file information management method capable of efficiently reading and writing data from and to each storage medium. .

[0002]

2. Description of the Related Art In a computer system used for an electronic library or the like, a large-capacity, high-performance storage medium library device has been used. As such a storage medium library device, a large number of detachable (removable) and portable (transportable) storage media (eg, CD-ROM or DVD) are stored in respective storage shelves so as to be freely taken in and out. With a storage body,
It comprises one or more removable drives for reading and writing (i.e., driving) data to and from a designated storage medium, and a transport mechanism for transporting the designated storage medium between the housing, the drive, and the like. There is something. Various operations of the entire storage medium library device are controlled by a library controller based on instructions from a host device such as a personal computer.

In a system including such a storage medium library device, that is, in a storage medium library system, when a data write command is given from the host device, one of the drives is designated according to the data write command. Write data to the storage medium. Each time such data is written, the host device stores the contents of the data, the write position and write range of the data in the storage medium, and the storage medium in the file management area of the storage medium. The storage shelf number and the like are written as file management information. Also, when reading the data stored in the storage medium in this way, the file management information of the storage medium is referred to, and various records related to the data reading are added to the file management information. Become. In a conventional storage medium library system of this kind, every time data is read from or written to a storage medium specified by a user, not only the operation of transporting the specified storage medium to the drive, but also the storage medium The operation of reading / writing file management information from / to the file management area and the operation of reading / writing data from / to the data area of the storage medium have all been executed via the host device.

[0004]

That is, in this type of storage medium library system using a removable storage medium, each time data is read or written from or to a specified storage medium, the storage medium is stored in the storage medium. Prior to processing on the data area of the medium, the host device always performs a large number of seek operations on the file management area of the storage medium. Due to such a large number of seek operations to the file management area, the required access time to the storage medium is prolonged, and therefore the operating efficiency of the system, especially the operating efficiency of the drive, has been greatly reduced. . Further, in the storage medium library system, when exchanging a storage medium already stored for another storage medium (medium change), an operation of accumulating data on the stored storage medium in the storage medium library device is performed. Therefore, during the medium change time, data sent from the host device is not accepted by the storage medium library device, which further limits the operating efficiency of the system. Further, as described above, since the host device writes, updates, or refers to the file management information, the load on the host device has increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a file information management method in a storage medium library system capable of efficiently reading and writing data from and to a removable storage medium. Aim.

[0006]

SUMMARY OF THE INVENTION A file information management method in a storage medium library system according to the present invention is characterized in that a storage body for storing a large number of detachable and portable storage media in respective storage shelves so as to be freely taken in and out. Storage library device including a removable drive for reading and writing data from and to a storage medium, and a transport mechanism for transporting a specified storage medium between the housing and the drive, and the storage medium library device , A library controller that controls the storage medium library device according to an operation command from the host device, and data read / write from both the host device and the storage medium library device. Storage medium library system comprising a non-volatile data storage device When storing a storage medium in the drive, reading predetermined information from the storage medium and storing it in the data storage device; and when the host device issues a data read / write command, the data storage device Reading and writing predetermined information stored in the data storage device, and writing the predetermined information stored in the data storage device into the storage medium when removing the storage medium from the drive.

According to the present invention, a storage medium library system with high data read / write processing efficiency can be provided. When the storage medium is accommodated in the drive, predetermined information is read from the storage medium, and the information is stored in the data storage device. At the time of data read / write, the information stored in the data storage device is accessed and the information is updated. Data access to the data storage device is faster than data access to a storage medium via a drive. Therefore, the information stored in the data storage device is accessed and updated without directly accessing the storage medium. Then, when removing the storage medium from the drive, the information stored in the storage device is collectively written to the storage medium. As described above, by minimizing data access to the storage medium, the operation efficiency of the storage medium library system can be improved.

The invention can be constructed and implemented not only as a method invention but also as an apparatus invention. Further, the present invention can be implemented in the form of a program of a processor such as a computer or a DSP, or can be implemented in the form of a storage medium storing such a program.

[0009]

An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram schematically showing an overall configuration of a storage medium library system according to an embodiment of the present invention. In FIG. 1, a storage medium library device 3 stores a large number of removable (transportable) storage media (media) 4 such as CD-ROMs and DVDs in respective storage shelves. A housing 6, one or more (in the illustrated example, a plurality of) removable drives 7 for reading and writing (in other words, driving) data to and from the designated storage medium 4, and the storage 6 and the drive 7 Storage medium 4 specified between
And a transport mechanism 5 for transporting. Various operations of the entire media library device 3 are controlled by the library controller 2. The library controller 2 is connected to a host device 1 composed of, for example, a personal computer.

Further, in the storage medium library system shown in FIG. 1, the library controller 2 includes, in addition to the main memory 21,
For example, a high-speed cache memory 22 (that is, an HDD cache memory) constituted by a hard disk (HDD) which is a large-capacity nonvolatile memory is connected. In the present embodiment, the cache memory 2
2 stores file management information on each file of each storage medium 4 stored in the storage medium library device 3. The file management information includes various information such as the content of each data file stored in the storage medium 4, a writing position and a writing range, and a storage shelf number in the storage unit 6 in which the storage medium 4 was stored. .

As shown schematically in FIG. 2A, a main memory 21 of the library controller 2 has a file management information area 21a for storing file management information of each storage medium 4 driven by the drive 7. And data to be written or read by the user via the host device 1, that is, a user data area 21b for storing user data. As schematically shown in FIG. 2B, the cache memory 22 stores the file management information cache area 2.
2a and a user data cache area 22b.
The file management information cache area 22a is for copying the file management information of each storage medium 4 stored in the file management information area 21a of the main memory 21 and storing it in a high-speed readable manner. Is for copying the user data stored in the user data area 21b of the main memory 21 and storing it in a high-speed readable manner.

In the storage medium library system of the present invention configured as described above, the library controller 2 operates as follows. FIG. 3 shows a data write request given by a user via the host device 1.
9 is a flowchart illustrating an example of a data write (write) processing sequence executed by the library controller 2 according to the present embodiment to write user data to a specified storage medium 4. First, in step S1 of FIG. 3, the user data transmitted via the host device 1 is stored in the user data area 21b of the main memory 21, and the file management information on the user data is stored in the file of the main memory 21. It is stored in the management information area 21a. In the next step S2, it is determined whether or not the specified storage medium 4 has already been mounted (loaded) on the drive 7. The specified storage medium 4 is not mounted on the drive 7 (step S2
Is negative), the specified storage medium 4 is mounted on the drive 7 in step S3. Then, proceeding to step S4 following step S3, it is determined whether or not the file management information exists in the storage medium 4 mounted on the drive 7. If the file management information exists in the storage medium 4 (the determination result in step S4 is YES), in the next step S5, the file management information of the mounted storage medium 4 is replaced with the file management information of the cache memory 22. The data is copied and expanded in the cache area 22a. Through these steps S2 to S5, every time a new storage medium 4 is mounted on the drive 7, the file management information of the storage medium 4 is copied to the file management information cache area 22a of the cache memory 22. As described above, by copying the file management information of the storage medium 4 mounted on the drive 7 to the cache memory 22, it is only necessary to access the file management information copied to the cache memory 22 thereafter. Storage medium 4 for each seek
There is no need to access its own file management information.
Therefore, the data writing process can be significantly speeded up.

In the step S4, the storage medium 4
It is determined that the file management information does not yet exist (that is, for example, when the mounted storage medium 4 is a medium on which no file is recorded yet) or after the processing of step S5 ends. Is
The write data receiving process of step S6 is performed. If it is determined in step S2 that the specified storage medium 4 is already mounted on the drive 7, the processing in steps S4 and S5 has already been performed. Then, the process directly goes to the write data receiving process in step S6.

In the write data receiving process at step S6, the file management information stored in the file management information area 21a of the main memory 21 at step S1 is used to expand the data in the file management information cache area 22a of the cache memory 22. Update the file management information that has been set. Similarly, in step S1, the user data stored in the user data area 21b of the main memory 21 is stored in the cache memory 2.
2 is written to the user data cache area 22b. When the write data receiving process in step S6 is completed,
In step S7, the user data written in the user data cache area 22b of the cache memory 22 is written to the mounted storage medium 4. Then, in the next step S8, it is determined whether or not an instruction to demount (remove) the storage medium 4 from the drive 7 has been given. If the demounting of the storage medium 4 is instructed (the determination result in step S8 is YES), in step S9, the updated file written in the file management information cache area 22a of the cache memory 22 is updated. The management information is written to the storage medium 4 to be demounted. Thereafter, in step S10, the storage medium 4 is demounted from the drive 7, and returned to, for example, the storage shelf where the storage medium 4 was originally stored. If the instruction to demount the storage medium 4 has not been issued in step S8 (the determination result in step S8 is NO), the current data write processing sequence is terminated without demounting the storage medium 4, and the storage is performed. Wait for the next write request for the medium 4. As described above, the data write processing sequence shown in FIG. 3 ends.

In this embodiment, as described above, after the file management information of the cache memory 22 (that is, the latest file management information on the storage medium 4 on which the writing process has been performed) is written to the storage medium 4 in step S8,
Since the storage medium 4 is returned to the original storage shelf or the like, even when such a removable storage medium 4 is taken out of the storage medium library device 3, the storage medium 4 is used. The latest file management information can always be taken out in a recorded state. Therefore, there is no inconvenience that the storage medium 4 is taken out of the storage medium library device 3 without having the latest file management information.

FIG. 4 shows data executed by the library controller 2 according to the present embodiment in order to read data from the specified storage medium 4 in response to a data read request given by a user via the host device 1. It is a flowchart which shows an example of a reading (read) processing sequence. First, in step S11, it is determined whether the specified storage medium 4 is already mounted on the drive 7. If the specified storage medium 4 is not mounted on the drive 7 (the determination result in step S11 is NO), the specified storage medium 4 is mounted on the drive 7 in step S12. Then, proceeding to step S13 following step S12, the file management information stored in the storage medium 4 mounted on the drive 7 is copied and expanded in the file management information cache area 22a of the cache memory 22. Through these steps S11 to S13, each time a new storage medium 4 is mounted on the drive 7, the file management information of the storage medium 4 is copied to the file management information cache area 22a. As described above, by copying the file management information of the storage medium 4 mounted on the drive 7 to the cache memory 22, it is only necessary to access the file management information copied to the cache memory 22 thereafter. The trouble of accessing the file management information of the storage medium 4 itself for each seek can be saved. Therefore, as in the above-described data writing process, the data reading process for the storage medium 4 can be significantly speeded up.

After the process of step S13 is completed, the process of step S14 is performed. In step S11, it is determined that the specified storage medium 4 is already mounted on the drive 7 (step S11).
Is YES), step S13
Has already been performed, so that step S
From step 11, the process directly goes to the processing in step S14. In the process of step S14, by searching for the file management information of the storage medium 4 copied to the file management information cache area 22a in the step 13, the data read from the storage medium 4 is requested ( The position (address or the like) where the read request data) is written is found, and thereafter, the read request data is read from the storage medium 4 and
Copy to the user data cache area 22b.
In the next step S15, the read request data copied to the user data cache area 22b in step S14 is transmitted to the host device 1. When the read request data is copied to the user data cache area 22b in step S14, the prefetch process may be executed by copying data subsequent to the read request data.

After transmitting the read request data to the host device 1 as described above, in the next step S16,
It is determined whether or not an instruction to demount the storage medium 4 has been issued from the drive 7. When the demount of the storage medium 4 is instructed (the determination result of step S16 is YES), the file management information written in the file management information cache area 22a of the cache memory 22 is demounted. Writing to the storage medium 4. Thereafter, in step S18, the storage medium 4 is demounted from the drive 7 and returned to, for example, the storage shelf where the storage medium 4 was originally stored. If the instruction to demount the drive 8 of the storage medium 4 has not been issued in step S16 (the determination result in step S16 is NO), the present data read processing sequence ends without demounting the storage medium 4. , And waits for the next read request for the same storage medium 4. As described above, the data read processing sequence shown in FIG. 4 ends.

As described above, in this embodiment, as described above, in step S17, the cache memory 2
2 (that is, the latest file management information relating to the storage medium 4 that has been read out).
Since the storage medium 4 is returned to the original storage shelf or the like after being written in the storage medium 4, even when such a removable (removable) storage medium 4 is taken out of the storage medium library device 3, The storage medium 4 can always be taken out with the latest file management information recorded.
Therefore, even in this case, there is no inconvenience that the storage medium 4 is taken out of the storage medium library device 3 without the latest file management information.

In the above-described embodiment, the storage medium library system including the single storage medium library device 3 has been described. However, the present invention is not limited to this. For example,
A storage medium library array system (RAI) having an array configuration by combining a plurality of the storage medium library devices 3
L: Redundant Arrays of Inexpensive Libralies). In the above-described embodiment, the example in which the HDD cache memory 22 is constituted by only one HDD is shown. However, by configuring the HDD cache memory 22 with two or three HDDs, the HDD cache memory 22 can be duplicated or The use of a triple mirror structure is effective in protecting file management information.

[0022]

As described above, according to the present invention, the seek operation to the file management area, which occurs every time user data is read / written from / to the removable storage medium, can be performed by mounting the storage medium. Since it is performed only at the time of demounting, there is an excellent effect that data read / write efficiency of the storage medium library system is improved. Further, by storing the user data sent from the host device in the HDD cache memory, the writing of the user data can be executed without interruption even when the storage medium is replaced. The effect that operation efficiency improves is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing an overall configuration of a storage medium library system according to an embodiment of the present invention.

FIG. 2 is an embodiment of a configuration of a main memory and an HDD cache memory of a library controller,
2A shows the configuration of the main memory, and FIG.
1 shows a configuration of a D cache memory.

FIG. 3 is a flowchart illustrating an example of a data write processing sequence executed by a library controller.

FIG. 4 is a flowchart illustrating an example of a data read processing sequence executed by a library controller.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Host apparatus, 2 ... Library controller, 3 ... Storage medium library apparatus, 4 ... Storage medium, 5 ... Transport mechanism,
6: storage body, 7: drive, 21: main memory, 22
… HDD cache memory

Claims (3)

[Claims] 1. A storage body for storing a large number of removable and portable storage media into and out of respective storage shelves, a removable drive for reading and writing data from and to a specified storage medium, and A storage medium library device including a transport mechanism for transporting a specified storage medium between a storage body and a drive, a host device for giving an operation command to the storage medium library device, and a host device for responding to an operation command from the host device A storage medium library system comprising: a library controller that controls the storage medium library device by using a non-volatile data storage device that can read and write data from both the host device and the storage medium library device. When a storage medium is stored in the storage medium, predetermined information is read from the storage medium and the data is read out from the storage medium. Storing in a storage device; reading and writing data to and from predetermined information stored in the data storage device when a data read / write command is issued from the host device; and taking out a storage medium from the drive Writing the predetermined information stored in the data storage device into the storage medium. 2. The file in the storage medium library system according to claim 1, wherein the predetermined information stored in the data storage device includes at least file management information used when storing data in a storage medium. Information management method. 3. A storage body for storing a large number of removable and portable storage media into and out of storage racks, a removable drive for reading and writing data from and to a specified storage medium, and A storage medium library device including a transport mechanism for transporting a specified storage medium between a storage body and a drive, a host device for giving an operation command to the storage medium library device, and a response to an operation command from the host device A library controller that controls the storage medium library device, a non-volatile data storage device that can read and write data from both the host device and the storage medium library device, a storage medium housed in the drive, When predetermined information is transmitted / received to / from the data storage device and data read / write is performed from the host device, Storage media library system comprising a control means for performing data read out from a predetermined information stored in the data storage device.