JPH10232800A - Magnetic tape storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable parallel access by shortening the waiting time of user access to the same data while effectively and efficiently using a magnetic tape cartridge with a little non-used areas concerning a magnetic tape storage device for performing magnetic recording while using the mass data recordable magnetic tape cartridge. SOLUTION: While also including a data area spread over plural cartridges CT1 and CT2 as the range of 'variable virtual volume' (the managing unit of data having variable or fixed size corresponding to data capacity), this virtual volume LV1 is handled similarly to the variable virtual volumes dividing one cartridge of magnetic tape as well and data are managed for the unit of these variable virtual volumes. Besides, by storing data while dividing them into plural cartridges and by preparing plural decks MTE1 and MTE2, when the cartridges to be accessed are different, even in case of the same continuous data, the access from users more than two is enabled and parallel processing is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic tape storage device, and more particularly to a magnetic tape storage device such as a magnetic tape device or a magnetic tape library device for performing magnetic recording using a magnetic tape cartridge capable of recording a large amount of data. .

[0002]

2. Description of the Related Art In this type of magnetic tape storage device, a magnetic tape for one magnetic tape cartridge is conventionally defined as one volume.
As a magnetic recording method, not only a magnetic tape device in which a magnetic tape makes one reciprocation and two-way recording is performed, but also a magnetic tape device in which a magnetic tape makes several reciprocations and multi-track recording is conceivable. Because the capacity per unit has increased significantly, the magnetic tape of one cartridge is virtually divided into a plurality of areas, and one area is defined as one volume for reasons such as effective use of magnetic tape cartridges and ease of data management. (Called a virtual volume method).

[0003] When recording data having a capacity that cannot be stored in one cartridge on a magnetic tape cartridge, the data is continuously recorded in several cartridges (several volumes). The joint between cartridges (volume to volume) is assured by recording data such as the recognition information of the volume corresponding to the existence of continuous data.

[0004] The management of the magnetic tape cartridge is as follows.
If the number of cartridges is small, it can be manually performed by a human. However, if the number of cartridges is several hundred or more, it is performed using software or a library device different from the magnetic tape subsystem.

[0005] Further, the operation using the autochanger includes the operation of continuously recording a large amount of data covering several cartridges in the order of the cartridges in the magazine and the backup of certain data by changing the cartridges one by one at regular intervals. Work (data generation management). In this case, as for the cartridges in the magazine, one cartridge is treated as one volume.

[0006]

An object of the magnetic tape cartridge is to effectively use up the magnetic tape for one cartridge with less wasteful area. Especially 1
When writing or reading a large amount of data that cannot be stored on a magnetic tape for a cartridge, if one cartridge of the magnetic tape cartridge is used as one volume as in the conventional case, the second and subsequent magnetic tapes are used. This will increase the useless area above.

Further, as a feature of the magnetic tape cartridge, data is recorded sequentially from the beginning of the magnetic tape, and when a certain user accesses data in the magnetic tape cartridge, another user may access the data in the magnetic tape cartridge. Cannot access the same data and other data. Therefore, the larger the amount of recorded data, the longer the waiting time when the user accesses.

It is an object of the present invention to provide a magnetic tape device and a magnetic storage device such as a magnetic tape library device which can effectively use the magnetic tape of a magnetic tape cartridge without waste.

Another object of the present invention is to provide a magnetic tape device and a magnetic tape library device using a magnetic tape cartridge, which can shorten the data access time and use the magnetic tape cartridge efficiently. An object of the present invention is to provide a magnetic storage device such as a magnetic tape library device.

[0010]

When writing or reading a large amount of data that cannot be accommodated in a single magnetic tape cartridge to or from a magnetic tape, the magnetic tape of the single cartridge is finely divided into a "variable virtual volume" (data capacity). When data is recorded in the required number of variable virtual volumes or when one cartridge is recorded as one volume, the data to be recorded is added to each volume in addition to the data to be recorded. Control information is written and read, and as the number of volumes increases, user's volume management also becomes troublesome.

Therefore, in the present invention, the range of the variable virtual volume is considered to include a data area extending over a plurality of cartridges of two or more cartridges. According to the present invention, this expanded virtual volume in a broad sense can be handled in the same manner as the above-mentioned variable virtual volume in a narrow sense obtained by dividing a magnetic tape for one magnetic tape cartridge. Perform in volume units.

If one large volume of continuous data is recorded on a magnetic tape of one cartridge, one user occupies the data at the time of use, and another user accesses the data. It will take some time. Therefore, when the data is large across a plurality of cartridges, the magnetic tape is divided by a virtual volume having a size that can divide one cartridge into a plurality of areas, and one data is divided and recorded on the magnetic tape of a plurality of cartridges. If data is recorded by this method, if there are a plurality of magnetic tape devices, two or more users can access even if data having the same name is accessed by different cartridges. That is, by preparing a plurality of decks, even if one continuous data is accessed to a different cartridge, the processing can be performed in parallel.

When an autochanger is used, the control unit checks the data connection, and the user can access by specifying only the virtual volume without being aware of the cartridge. Also, when a library device is used, the variable virtual volume and the magnetic tape cartridge are associated (managed) by the library and magnetic tape control devices, so that the user can freely access data if only the volume is considered. And the burden on the user is reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a magnetic storage device that performs control using an extended variable virtual volume according to the present invention will be described.
A specific description will be given mainly taking a magnetic tape library device as an example.

FIG. 1 is a conceptual diagram showing divisional storage of a large amount of data in a plurality of cartridges. FIG.
(A) shows a state in which there is data D1 that cannot be accommodated in the magnetic tape 11 of one magnetic tape cartridge CT1, which is divided and stored in the magnetic tape 12 of another magnetic tape cartridge CT2. The tape 11 of the cartridge CT1 stores part of the target data D1 as D1-1, and the tape 12 of the cartridge CT2 stores the remaining part D1-2 of the data D1 halfway of the magnetic tape 12. The area surrounded by the dotted line in which the data D1 is stored is called one virtual volume LV1, and is handled as one volume which is a control unit. In the remaining area of the magnetic tape 12, a virtual volume for storing data other than the data stored in the virtual volume LV1 can be created. In the figure, virtual volumes LV2 and LV3 are used, and data D2 and D3 are stored respectively. ing.

In the case of FIG. 1A, one data D1 that cannot be accommodated in one cartridge is divided and stored in two cartridges CT1 and CT2, and one virtual volume LV is stored.
Although it is assumed to be 1, it is also possible to handle data magnetically recorded over three or more cartridges as one volume.

FIG. 1B shows two data D1 and D2.
Is stored over two cartridges CT1 and CT2. In the cartridge CT1, the data D1 and the data D2 are partially D1-1 and D1-2, respectively.
The data D1 and the rest of the data D2 are stored as D1-2 and D2-2 in the cartridge CT2. Also in this case, the areas surrounded by the dotted lines are each treated as one volume, and are referred to as a virtual volume LV1 and a virtual volume LV2. FIG.
The data can be stored over several cartridges and handled as the same volume without being limited to the two-cartridge divided storage as in (b).

FIG. 2 shows the format of the magnetic tape 10. At the leading end of the magnetic tape 10, cartridge control information 21 including information such as a cartridge name, the number of virtual volumes and virtual volume names in the cartridge, the presence or absence of a free area, and a free capacity is written. The virtual volume 20 on the magnetic tape starts with volume control information 2 including a virtual volume name and information such as the size of the virtual volume on the magnetic tape 10.
2 is recorded, followed by a data area 23 for recording data. At the end of the virtual volume 20, volume continuity information 24 consisting of information indicating whether the virtual volume 20 ends with the cartridge or is continuously recorded on another cartridge, and a cartridge name when the volume is continuous, is provided. Has been recorded.

FIG. 3A shows a table 3 of virtual volume management data held in the magnetic tape library controller.
Indicates 0A. Necessary as management data are the cell address 31 where the cartridge is stored, the cartridge name 32, the number 33 of virtual volumes recorded in the cartridge, the virtual volume name 34, and the virtual volume of the cartridge. This is the virtual volume continuation information 35 such as information on whether the recording is completed or continuous recording on another cartridge, and the cartridge name if continuous. These pieces of information are arranged in the order of cell addresses and stored as a table 30A.

FIGS. 3B and 3C show management tables 30B and 30C for efficiently controlling the magnetic tape library device, based on the management table 30A shown in FIG. 3A. create.

FIG. 3B is a correspondence management table 30B for virtual volumes and magnetic tape cartridges. The virtual volume name 36 is designated, the number of divisions 37, the name of the stored cartridge, the address on the tape, and the like.
The capacity information 38 can be easily checked. The magnetic tape control device receives the designation of the virtual volume name from the user, checks the management table 30B, and presents the cartridge name to the user. The loading of the magnetic tape cartridge is performed by the user.

FIG. 3C shows a cell management table 30C in the magnetic tape library apparatus, which facilitates checking of the name 3a of the cartridge stored in the cell, the presence / absence of a free area 3b, and the free capacity 3c.

When managing a virtual volume only with a magnetic tape device without using a magnetic tape library device, the magnetic tape control device or virtual volume management software uses these management tables 30.
By creating and managing A, 30B, and 30C, management of virtual volumes is enabled. However, the cell address is not required as data, so that it is deleted.

FIG. 4 shows a processing flow for dividing and storing the large amount of data shown in FIG. 1 into a plurality of cartridges. However, this flow is a process in the magnetic tape library device, and is performed by the magnetic tape library control device.

When a data write instruction is issued from a user, a virtual volume name is input 401, and whether it is a new write or a rewrite is determined in the management table 30B shown in FIG. Proceed to 403
The free area and free space of the magnetic tape cartridge are checked from the management table shown in FIG. 3C, and the virtual volume capacity and the free space are checked against the size of the data to be written.
Divide the virtual volume, determine the first magnetic tape cartridge 404. Obtain the cell address from the name of the first magnetic tape cartridge 405, load and write the magnetic tape 406, and end the write processing on the magnetic tape. After that, the presence or absence of remaining data is checked 407,
If there is, the free area and free capacity of the magnetic tape cartridge are checked from the management table 30C of FIG. 3C, the next tape is selected 408, the continuous information is written to the magnetic tape, and the management table is updated 409, The processing shifts to the next magnetic tape cartridge.

In the judgment step 407, if there is no remaining data, the continuous information is written to the magnetic tape, the management table is updated, and the process is terminated (416). At the time of the determination in the process 402, if it is rewriting, the cartridge name and the cell address are obtained from the management table 30B shown in FIG.
11. Proceed to magnetic tape write processing. The difference from the new write is that when the data to be rewritten becomes larger than the data stored before the rewriting, the capacity of the virtual volume is changed when the capacity of the initial virtual volume is exceeded. 3 (c) management table 3
The next tape is selected 415 by checking the free area and free capacity of the magnetic tape cartridge from 0C.

Here, the next tape is selected in consideration of a case where the magnetic tape library apparatus is down and humans have to perform work, and select a tape having a cell address and / or a cartridge name as close as possible. It is better to keep it.

When this operation is performed by the magnetic tape device, as described in the description of FIG. 3, the management table excluding the cell address must be created and managed by the magnetic tape control device or the virtual volume management software. Is possible.

FIG. 5 conceptually shows the overall configuration of a magnetic tape library device embodying the present invention, and shows an example of data division into a plurality of magnetic tape cartridges, management by the magnetic tape library device, and parallel access. Is mainly shown.

First, for data division, data D1 for one magnetic tape cartridge is shown in FIG.
In the dividing method shown in FIG.
Divided into 4 cartridges of T4, virtual volume LV
It is set to 1. The cartridges CT1 to CT4 are stored in the cartridge storage cell frame 52 of the magnetic tape library device 50.

On the other hand, the magnetic tape library device 50
A robot 51 for transporting the magnetic tape cartridge CT,
Cell frame 5 for storing magnetic tape cartridge CT
2. Decks (magnetic tape devices) MTE1 and MTE2 for driving the magnetic tape cartridge CT and a magnetic tape library control device 54 for controlling them.

The basic control of the magnetic tape library controller 54 is performed by managing 55 by associating each cartridge with a virtual volume and storing the position of the cartridge in the cell frame as data in a nonvolatile memory. is there. In other words, the magnetic tape library control device 54 accesses automatically by referring to the management data only by specifying the volume of the user.

Next, the movement of the cartridge when two users access the same data is illustrated in the lower left part of FIG. The solid line 57 indicates the movement of the cartridge CT1, and the dotted line 58 indicates the movement of the cartridge CT2. Now, user 1 is on deck MTE1, and user 2 is on deck MTE2.
And user 1 accesses first,
The cartridge CT1 is moved and loaded 57 to the deck MTE1 by the robot 51 in the magnetic tape library device 50, and the data is accessed. Cartridge CT1
After the access on the deck MTE1 is completed, the robot 51 moves and loads 57 to the deck MTE2 by the robot 51. After the access of the cartridge CT1 on the deck MTE2 starts, the cartridge CT2 is moved by the robot 51 to the deck MTE1.
Is moved and loaded 58. After the access by the deck MTE2 is completed, the cartridge CT1 is returned to the original position of the cell frame 52 57, and the cartridge CT2 is returned to the deck MT
After the access at E1 is completed, it is moved and loaded 58 to the deck MTE2. This procedure is performed for cartridges CT3 and CT4.
Is performed in the same manner, and parallel access to the same data proceeds.

FIG. 6 shows a flow of a parallel access process to data spanning a plurality of cartridges in the magnetic tape library device 50. When a data access request is issued from the user 601, the magnetic tape library control device 54 acquires the name of the virtual volume for which the access request was made 602, and uses the table 30 A shown in FIG. Step 603: acquiring name and virtual volume continuous information. Then, it is confirmed 604 whether another user is using the magnetic tape cartridge on which the target virtual volume is recorded. If the cartridge is not in the free state, a wait state is entered 605, and if the cartridge is in the free state, the current position of the cartridge is confirmed 606, and then the robot 51 is controlled to pick up the cartridge 608.

The cartridge 51 is moved and loaded by the robot 51 to the deck used by the user 607, after the data access is completed by the user 608, the continuous information of the virtual volume is obtained 609, and the cartridge unloading process is started 610. When another user is in the cartridge free waiting state 611, the cartridge is held in the unload completed state 612, and after reporting the cartridge free 613, the cartridge waits 614 for the movement of the cartridge according to the instruction of the other user. If there is no cartridge free waiting state by another user 615, the cartridge is returned to the original cell 616, and the cartridge free report is made 617. Then, the presence / absence of the next cartridge is determined 618 based on the continuous information of the virtual volume, and if there is, the process proceeds to the next cartridge 619, and if not, the process ends 620. Note that when this process is performed only by the magnetic tape device, the cartridge is transported by the user himself.

[0036]

As described above, according to the present invention, when a large amount of data is written to or read from a magnetic tape,
By considering the data area extending over two cartridges or a plurality of cartridges as the range of the variable virtual volume, the virtual volume can be packed and recorded so that the unused area of the magnetic tape is reduced. Can effectively and effectively use the unused portion. By using these variable virtual volumes, data management can be performed on a virtual volume basis.

In the case of large data having a plurality of cartridges, the data is divided into a plurality of cartridges and recorded, and a plurality of magnetic tape devices are prepared so that data of the same name can be accessed by two or more users. It becomes possible.
In other words, sequential access processing of sequential data becomes possible, and the waiting time for the user to access becomes shorter.

Furthermore, if this control method is used to manage cartridges and virtual volumes with a control device in a magnetic tape storage device such as a magnetic tape library device or a magnetic tape device, or with management software, the user cares about the cartridge. You can access the required data simply by specifying the volume without having to do it.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing divided storage of large-capacity data in a plurality of cartridges. FIG. 1A is a conceptual diagram in which one data is divided, and FIG. 1B is a conceptual diagram in which two data are divided.

FIG. 2 is a format diagram of a magnetic tape.

3A is a conceptual diagram of a virtual volume management table in the magnetic tape library control device, FIG. 3B is a conceptual diagram of a virtual volume name correspondence management table, and FIG. 3C is a conceptual diagram of a cell management table.

FIG. 4 is a processing flowchart of divided storage of a large amount of data in a plurality of cartridges.

FIG. 5 is a schematic diagram showing an example of divided storage of large-capacity data in a plurality of cartridges and an example of an embodiment of a magnetic tape library device.

FIG. 6 is a flowchart of parallel access processing to data across a plurality of cartridges.

[Explanation of symbols]

10, 11, 12: magnetic tape, 20: virtual volume, 21: cartridge control information, 22: volume control information, 23: data area, 24: volume continuous information, 30A: virtual information management table, 30B: virtual volume name correspondence Management table, 30C: Cell management table, CT1, CT2, CT3, CT4: Magnetic tape cartridge, D1, D2, D3: Data, LV1, LV
2, LV3: virtual volume, MTE1, MTE2: magnetic tape device

Claims (5)

[Claims] 1. A magnetic tape storage device which divides a magnetic tape of one cartridge into a plurality of variable-capacity virtual volumes smaller than the magnetic tape capacity and records and manages the divided volumes.
A magnetic tape storage device comprising: a control unit that manages an area extending over one cartridge or a plurality of cartridges as one virtual volume. 2. A system according to claim 1, further comprising control means for dividing one virtual volume into a plurality of variable capacities smaller than the virtual volume, and allocating and managing the divided virtual volumes across magnetic tapes of a plurality of cartridges. The magnetic tape storage device according to claim 1. 3. The magnetic tape storage device according to claim 1, wherein the capacity of the virtual volume is determined by the capacity of individual data to be recorded, and is a virtual volume made variable. . 4. The magnetic tape storage device according to claim 1, wherein said control means performs data management on a virtual volume basis. 5. The magnetic tape storage device according to claim 4, wherein the control means accesses the same data in parallel by recording data on magnetic tapes of a plurality of cartridges.