JPH0969028A - Magnetic tape cartridge control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the magnetic tape cartridge control system, which has a magnetic tape device performing magnetic recording by using a magnetic tape cartridge, automatically perform generation management and maintenance for data without making a user aware of them by effectively and efficiently using one magnetic tape cartridge with a less unused area and performing the generation management for the data with one magnetic tape cartridge. SOLUTION: The magnetic tape of one magnetic tape cartridge is divided into a plurality of variable-capacity areas (variable data capacity dependent logical volume) and a magnetic tape controller 20 performs management by the areas. Further, the generation control of a data backup is performed with one magnetic tape cartridge by regarding one variable data capacity dependent logical volume as one generation. Further, when the frequency of access to a data capacity dependent logical volume exceeds a set threshold value, its data are saved in free areas of its tape or another tape to maintain the data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape device,
In particular, the present invention relates to a magnetic tape cartridge control system for performing magnetic recording using a magnetic tape cartridge capable of recording a large amount of data.

[0002]

2. Description of the Related Art Conventionally, in a magnetic tape cartridge, one volume is defined as one volume, and a magnetic tape controller also has one
The volume is recognized as one volume. That is, the magnetic tapes have a one-to-one correspondence physically and logically.

When the number of windings is small, a person manually manages the magnetic tape cartridge. When the number of windings exceeds several thousand, it is managed by software other than the magnetic tape subsystem or a magnetic tape library device. Further, unlike the magnetic tape library device, a plurality of magnetic tape cartridges are placed in a magazine and the magnetic tape cartridges are sequentially handled by a magnetic tape autochanger.

On the other hand, magnetic recording on a 1/2 inch cartridge type magnetic tape is carried out in 18 tracks in one direction along the running direction of the magnetic tape.
There are two types of recording, that is, recording with only 8 tracks and recording with bidirectional 36 tracks. A magnetic head having a multi-track head element corresponding to the number of tracks is used in each case.

In recent years, not only one round trip (bidirectional recording) but also
A device has been devised in which a magnetic tape is reciprocated several times to record on a multi-track, and a large amount of data can be recorded on one roll of a magnetic tape cartridge.

Further, in terms of data protection of the magnetic tape, another tape is remade to prevent the data on the magnetic tape from being unreproducible due to deterioration of the magnetic tape. If the data on the tape is unfortunately destroyed, it is necessary to perform recovery by using special software or a device for data recovery. Both are labor-intensive and labor-intensive tasks.

Furthermore, there is a data control system in which a magnetic tape of one large-capacity magnetic tape cartridge, which corresponds to a plurality of magnetic tape cartridges in a conventional magnetic tape device, is divided by the capacity of one conventional magnetic tape cartridge. It is disclosed in Japanese Patent Laid-Open No. 05-73221.

[0008]

In the idea that one roll of magnetic tape cartridge corresponds to one volume, an unused area may be formed in the magnetic tape cartridge or the capacity may be insufficient depending on the size of data to be recorded. It is difficult to effectively use up one magnetic tape cartridge, and a method for effectively utilizing the magnetic tape cartridge is required.

Further, since the capacity of one roll of the magnetic tape cartridge is significantly increased, the wasteful area of the magnetic tape is increased if one roll of the magnetic tape cartridge is used as one volume as before. Therefore, the problem is to use the tape more efficiently so as to eliminate the useless area.

At present, the backup of system data is not limited to one generation ago, but one day ago, two days ago, ... 1
It's been around for several generations, like a week ago. This work requires one or several magnetic tape cartridges for each generation, and the user should be aware of each tape
There is no choice but to manage this book. Therefore, there is a demand for a method that can be automatically performed without bothering the user.

Further, since the magnetic tape is divided into several areas with a manageable capacity, it takes a long time to mount the magnetic tape cartridge on the magnetic tape device and access the desired area, and this time is shortened. It is also desired.

Another problem is to establish the ease of maintenance of the magnetic tape data that the user is currently doing. Due to the increase in the capacity of the magnetic tape, the number of accesses to one roll of the tape increases, the deterioration of the magnetic tape progresses, and the phenomenon of data destruction of the magnetic tape may occur. Therefore, it is necessary to save the data at an early stage.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic tape cartridge control system that effectively and efficiently uses one roll of magnetic tape cartridge.

It is another object of the present invention to provide a magnetic tape cartridge control system capable of automatically performing data generation management and data maintenance without the user being aware of it.

[0015]

In order to achieve the above object and to effectively utilize the magnetic tape cartridge, the present invention divides one magnetic tape cartridge into a plurality of logical volumes. Then, this logical volume is created so as to have a size depending on the capacity of the corresponding data. Hereinafter, this logical volume is referred to as a “data capacity dependent logical volume”. By using the data volume dependent logical volume, the logical volume can be packed and recorded so that the unused area of the magnetic tape is reduced. In the publications mentioned in the section of the prior art, the logical volume is fixed by the capacity of the whole one magnetic tape.

By thus dividing the magnetic tape into data volume-dependent logical volumes, data management shifts from the magnetic tape cartridge unit to the data volume-dependent logical volume unit. Therefore, the present invention provides means for managing and managing two associations between the magnetic tape cartridge and the data capacity dependent logical volume in the magnetic tape control device. Further, the management of the data volume-dependent logical volume in the magnetic tape autochanger is also performed by the magnetic tape control device, so that the exchange of the magnetic tape cartridges can be automatically performed.

Further, according to the present invention, for data generation management as well, several data volume dependent logical volumes can be created on the magnetic tape, and the magnetic tape controller can record the data of each generation. Since the generation management information is managed, the generation management of data, which has been performed by several magnetic tape cartridges up to now, is performed by the magnetic tape cartridge 1.
The volume makes it possible for the user to do without being aware of the generation.

The access time to the data capacity dependent logical volume changes depending on how the data capacity dependent logical volume is divided. When recording on a magnetic tape with multiple tracks, if a data capacity dependent logical volume is created with m reciprocations as one unit, the magnetic head will always be placed at the beginning of each data capacity dependent logical volume when the magnetic tape cartridge is mounted in the magnetic tape device. As a result, the access time to the data volume dependent logical volume can be shortened.

The maintenance of the data on the magnetic tape is automatically performed by the following method. The number of accesses to the data on the magnetic tape is managed by the magnetic tape controller, and when the value exceeds the set threshold value, the data is moved to the free area on the same tape or other tape to protect the data. . If an autochanger is used when moving to another tape, the cartridge in the autochanger is managed by the magnetic tape control device, so that the magnetic tape cartridge can be automatically replaced without any human replacement. You can move data to the area. In the publications cited in the above-mentioned prior art, only when a failure occurs in writing the data volume dependent logical volume area, writing is performed in the empty data capacity dependent logical volume area on the self tape.

[0020]

According to the present invention, by using the data volume dependent logical volume, one roll of the magnetic tape cartridge can be effectively used effectively with less unused portion.

Further, the user can perform the same data management as accessing the conventional magnetic tape cartridge (physical volume) by accessing the target data capacity dependent logical volume. In other words, by managing the data capacity dependent logical volume and the magnetic tape cartridge by the magnetic tape controller, the user only has to manage the data capacity dependent logical volume. Even when the autochanger is used, the same effect can be obtained by managing all the data volume dependent logical volumes in the autochanger by the magnetic tape controller.

In addition, the magnetic tape cartridge 1 for each generation
Generation control, which used a few or several windings, can be performed with one magnetic tape cartridge. The magnetic tape controller manages the data volume-dependent logical volume of one magnetic tape, so that a person can take a backup without being aware of the generation.

Further, in the case of performing magnetic recording by multi-track, if the data volume dependent logical volume is made in units of m round trips, the access time to the data is shortened.

Further, the data on the magnetic tape can be automatically and safely maintained.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic tape cartridge control system using a data volume dependent logical volume of the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual diagram in which the magnetic tape 1 is divided into data volume dependent logical volumes. Each data capacity dependent logical volume area 1a is composed of two parts: a control information part 1b of the data capacity dependent logical volume area and a data area part 1c. In the present invention, the capacity of this data capacity dependent logical volume is variable, and as shown in FIG. 1, data capacity dependent logical volumes of various capacities are created on the magnetic tape 1.

FIG. 2 shows a block diagram of an embodiment of a magnetic tape cartridge control system focusing on data management in data volume dependent logical volume units. That is, 10 is a host device such as a host computer, 20 is a magnetic tape control device, and 30 is a magnetic tape library device or a magnetic tape cartridge group device such as an autochanger. The magnetic tape controller 20
A host device interface 21 and a magnetic tape device interface 22 are provided to further control recording and transfer of data between the host device 10 such as a host computer and a magnetic tape cartridge group device 30 such as a magnetic tape library or an autochanger. It has a processing device 23. Although not shown, the processing device 23 is composed of a microprocessor and a memory device.

As described above, conventionally, each volume corresponds to one roll of the magnetic tape cartridge, and the magnetic tape control device has also accessed for each roll of the magnetic tape cartridge. However, by adopting the concept of the data volume-dependent logical volume, as shown in FIG. 2, the magnetic tape cartridge group device 30 accesses the mount unit 31 only once, but the data volume-dependent logical volume in the magnetic tape cartridge You will be able to access each volume. That is, the magnetic tape cartridge 1
The volume corresponds to multiple volumes.

A method of managing each data volume dependent logical volume will be described below. A "cartridge identifier" PVN ~ is attached to each magnetic tape cartridge, and a "data capacity dependent logical volume identifier" LVN ~ is added to the control area 1b shown in FIG. 1 for the data capacity dependent logical volume therein. Information relating these identifiers to each other, position information of the data volume dependent logical volume on the magnetic tape, etc. are stored in a non-volatile memory device (not shown) in the magnetic tape control device 20, and all are stored in the magnetic tape control device 20. Let me manage. Also, the magnetic tape controller 2
The magnetic tape control device 20 does not store all the management information in 0, but writes the data management information for each magnetic tape cartridge in the leading end portion of the magnetic tape and reads it when the magnetic tape cartridge is mounted. You can also use the method to manage the data.

Furthermore, a magnetic tape library device or a magnetic tape cartridge group device 30 such as an autochanger.
By using, the magnetic tape controller 20 can collectively manage not only one magnetic tape cartridge but also a large number of magnetic tape cartridges.

FIG. 3 shows a magnetic tape cartridge group device 3
As an example of 0, an auto changer is shown. A plurality of magnetic tape cartridges CTR are set in the magazine 31, and the magazine 31 is set in the auto change mechanism 32. Then, the movable portion of the automatic change mechanism 32 moves up and down, and the target magnetic tape cartridge can be mounted. At this time, the magnetic tape controller 20
Has position information of the magnetic tape cartridge in the autochanger in addition to the magnetic tape cartridge identifier information PVN ~ and the data capacity dependent logical volume identifier information LVN ~, and can freely access all the data capacity dependent logical volumes in the autochanger. It becomes possible to do. In this case, the magnetic tape cartridge control system has the same operation as the magnetic tape library device.

4 to 6 are diagrams showing a method of dividing a data volume dependent logical volume. FIG. 4 shows an example of multi-track magnetic recording. A magnetic head 40 capable of magnetic recording of 36 reciprocating tracks (18 tracks in one direction) is provided in a direction perpendicular to the running direction of the magnetic tape 1 by m
Moving to a stage, the magnetic tape 1 reciprocates in each stage to perform magnetic recording in multi-track. As a result, the magnetic tape 1 reciprocates m times, and the number of tracks on the magnetic tape 1 is
It will be mx 36 tracks. Here, m is a natural number.

FIG. 5 shows an example in which the size of the data volume dependent logical volume is determined according to the volume of data to be recorded. As shown, the data areas 1c-1, 1c-2,
1c-3, etc., respectively, control area information 1b-1,
The unused area of the magnetic tape can be reduced by packing the data volume dependent logical volumes 1a-1, 1a-2, 1a-3, etc. formed by adding 1b-2, 1b-3 etc. . However, it takes time to mount the magnetic tape cartridge on the magnetic tape device and then access the target data capacity dependent logical volume because the beginning position of each data capacity dependent logical volume is different on the magnetic tape. .

FIG. 6 shows the magnetic tape 1 as shown in FIG.
Shows a method of dividing i round trips (i is a variable and a natural number) into one data capacity dependent logical volume. In this case, an unused portion is formed in the data volume dependent logical volume area as compared with FIG. 5, and an unused area is produced in the magnetic tape. Since it is located at the beginning of, the access time to the data volume dependent logical volume is shortened.

FIG. 7 is a diagram showing generation management of data in one magnetic tape cartridge volume using a data volume dependent logical volume. FIG. 7A shows basic generation management using a data volume dependent logical volume. 1
One data capacity dependent logical volume is regarded as one generation, and generation information is added to the control information of each data capacity dependent logical volume. This figure shows an example of the first-generation data capacity-dependent logical volume 1aI, the second-generation data capacity-dependent logical volume 1aII, and the third-generation data capacity-dependent logical volume 1aIII. The magnetic tape control device 20 stores the recording information and the position information of the generation, and when the user backs up the data, the information is automatically referred to and the next information of the previous generation is stored. Record by shifting to the area. When the magnetic tape 1 becomes full, recording is started again from the first data capacity dependent logical volume. By doing this, backup for several generations
It can be taken with a wound magnetic tape cartridge.

FIG. 7B shows the generation management of data when one round trip is a data volume dependent logical volume of one generation. When the first generation, the second generation, ..., And the mth generation are recorded, the next m + 1th generation overwrites the first generation and then sequentially updates. Therefore, in this case, it is possible to record m-generation data on one roll of magnetic tape. The generation management method is the same as in the case of FIG.

FIG. 8 is a flow chart showing a method of maintaining data on the magnetic tape. In the present invention, as shown in FIG. 2, the number of times the magnetic tape cartridge is mounted once increases, and the number of times the magnetic tape is accessed increases accordingly.
Therefore, it is desirable to strengthen data maintenance from the viewpoint of preventing the data from being destroyed due to the deterioration of the tape. Therefore, the procedure of data maintenance will be described below with reference to FIG.

First, when the magnetic tape cartridge is mounted, the number of accesses to the data volume dependent logical volume is checked by the management information held by the magnetic tape control device or the data information recorded at the start end of the magnetic tape (801). ), And compares with the set threshold (80
2). As a result, if the access count does not exceed the threshold value, normal processing is performed (808) and the process ends, and if it exceeds, the free area in the tape is checked (80).
3). If there is a free area, the data to be recorded in the data buffer is read (805), and the data is written in the free area (806). Then, the information is corrected so that the area having the original data is prohibited (807). If there is no free area, report to the operator that the data will be saved to another tape (809), read the data into the data buffer (810), and correct the information so that the area where the original data existed is prohibited. (811), the self tape is demounted (812). Then mount another tape (813)
After that, the free area is checked (814), and if there is data writing (816), if not, another tape is mounted and the same processing is performed.

[0039]

As described above, according to the present invention, the user can access the data volume-dependent logical volume to manage the data in the same way as the conventional access to the magnetic tape cartridge (physical volume). Can be done.

By using the data volume dependent logical volume, one roll of magnetic tape cartridge
The unused area can be reduced and used efficiently. Further, generation management, which uses one or several magnetic tape cartridges for each generation, can be performed with one magnetic tape cartridge without human awareness.

Further, in the case of performing magnetic recording by multi-track, if the data volume dependent logical volume is made in units of m round trips, the access time to the data can be shortened.

Furthermore, by managing and checking the number of accesses, the data on the magnetic tape can be automatically and safely maintained, and the reliability of the magnetic tape can be easily improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of division of a variable data capacity dependent logical volume for one round trip of a magnetic tape.

FIG. 2 is a functional block diagram of a magnetic tape cartridge control system according to an embodiment.

FIG. 3 is a schematic perspective view of a magnetic tape cartridge autochanger.

FIG. 4 is a schematic diagram showing an example of division of a variable data capacity dependent logical volume by multi-track magnetic recording.

FIG. 5 is a schematic diagram showing an example of division of a variable data capacity dependent logical volume according to data length.

FIG. 6 is a schematic diagram showing an example of division of a multi-track variable data capacity dependent logical volume.

FIG. 7 is a schematic diagram showing generation management of data by a variable data capacity dependent logical volume, where (a) is a basic example and (b) is
Shows an example of one unit for one round trip.

FIG. 8 is a flowchart showing a data maintenance operation.

[Explanation of symbols]

1 ... Magnetic tape, 1a ... Data volume dependent logical volume area, 1b ... Control information area, 1c ... Data area, 10 ...
Host device, 20 ... Magnetic tape control device, 21 ... Host device interface, 22 ... Magnetic tape device interface, 23 ... Processing device, 30 ... Magnetic tape cartridge library device or magnetic tape cartridge autochanger, 31 ... Mounting part, 32 ... Storage part , 30A ... Magnetic tape cartridge autochanger, 31A ... Autochanger, 32A ... Magazine, 40 ... Magnetic head

Claims (8)

[Claims] 1. A magnetic tape cartridge control system characterized in that a magnetic tape of one roll of a magnetic tape cartridge is divided into a plurality of data capacity dependent logical volumes, and control is performed for each data capacity dependent logical volume. 2. The magnetic tape according to claim 1, wherein the capacity of the data capacity dependent logical volume is determined in proportion to the capacity of each data to be recorded, and the data capacity dependent logical volume is divided. Cartridge control method. 3. A magnetic tape cartridge is adapted to perform magnetic recording by reciprocating a plurality of times, and division of a data volume dependent logical volume can be performed in m reciprocating units (m is a positive integer and variable). The magnetic tape cartridge control system according to claim 1, which is characterized in that. 4. A magnetic tape controller comprising a magnetic tape controller for dividing one magnetic tape of a magnetic tape cartridge into a plurality of data capacity dependent logical volumes and controlling each of the data capacity dependent logical volumes. A magnetic tape cartridge control method characterized by managing (associating) a magnetic tape cartridge and a data volume-dependent logical volume recorded in the magnetic tape cartridge. 5. An automatic changer using a magazine for accommodating a plurality of magnetic tape cartridges is provided, and all magnetic tape cartridges and data volume dependent logical volumes in the magazine are managed by a magnetic tape controller, and data volume dependence is instructed. 5. The magnetic tape cartridge control system according to claim 4, wherein the magnetic tape control device accesses the logical volume. 6. A magnetic tape control device comprising a magnetic tape controller for dividing one magnetic tape of a magnetic tape cartridge into a plurality of data capacity dependent logical volumes, and controlling each of the data capacity dependent logical volumes. Is a magnetic tape which automatically manages the generation of data backup with one magnetic tape cartridge by allocating one data capacity dependent logical volume to one generation while keeping the capacity of the data capacity dependent logical volume constant. Cartridge control method. 7. A magnetic tape cartridge according to claim 3, wherein the data backup of a plurality of generations is managed by one roll of the magnetic tape cartridge by making the reciprocating unit constant and allocating each reciprocating unit to one generation. Tape cartridge control system. 8. The data storage system according to claim 1, wherein when the number of accesses to the data volume dependent logical volume exceeds a set threshold value, the data is saved to a free area on the self tape or another tape. Magnetic tape cartridge control system.