JPH01258121A - Logical volume realizing system - Google Patents

Abstract

PURPOSE:To eliminate necessity to be conscious of a case where a mapping information managing part falls in an unaccessible state by enabling the mapping information managing part set in the latest state to be recovered from a logical volume correspondent mapping information managing part. CONSTITUTION:A logical volume initialization means 5 segments a large capacity file medium 4 as a logical volume 41 and the logical volume correspondent mapping information managing part 42, and registers mapping information on the logical volume correspondent mapping information managing part 42 and a mapping information managing part 6. A logical volume name summary collection means 8 reads the summary of logical volume names in the large capacity file medium 4 assigned on the logical volume 41 setting the summary of large capacity medium names as key information, and a mapping information managing part recovery means 7 recovers the mapping information managing part 6 from the mapping information stored in the logical volume correspondent mapping information managing part 42 setting the summary of read logical volume names as the key information. In such a way, it is not required to be conscious of the case where the mapping information managing part falls in the unaccessible state, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a logical volume realization method, and particularly to a logical volume access means in a computer system equipped with a large-capacity file medium as a peripheral device.

The present invention relates to a logical volume realization method that maps a part of a large-capacity file medium to one logical volume by having a logical volume management means and a mapping information management section so that the large-capacity file medium appears as a plurality of logical volumes.

[Conventional technology]

Generally, in a logical volume realization method, a logical volume is realized by cutting out a part of a large-capacity file medium and mapping it into one logical volume. As a method for mapping a part of a large-capacity file medium to a logical volume, for example, there is a method of mapping a real file in a large-capacity file medium to a logical volume.

Conventionally, in this type of logical volume realization method, mapping information that governs the correspondence between each real file of a large-capacity file medium and the logical volume mapped to each real file is centrally managed by a mapping information management unit. This mapping information includes the volume serial number (large-capacity file medium name) of the large-capacity file medium, the real file name in the large-capacity file medium, the logical volume name corresponding to the real file name, the size of the logical volume, etc.

Generally, the mapping information management section is also provided in a large-capacity file medium, so in rare cases, for example, due to hardware deterioration (hereinafter simply referred to as failure) of the large-capacity file medium, the mapping information management section A situation may occur where access to the site becomes inaccessible.

In order for the logical volume realization method to be established as a system, some kind of countermeasures are necessary for such rare cases, but in the conventional logical volume realization method, there are Several basic methods are employed: a duplex method, a full dump method, and a combination of a duplex method and a full dump method.

The duplication method is a method in which the mapping information management section is duplicated on different large-capacity file media, and it is assumed that the duplicated large-capacity file media rarely become a failure at the same time. When a failure or the like occurs in one large-capacity file medium, the mapping information management section can be restored from the other large-capacity file medium.

In the full dump method, the muffing information management unit is evacuated to a separate wire such as a magnetic tape at an appropriate time, such as at the end of the day, and when a failure occurs, the muffing is evacuated from the separate wire. This allows the information management section to be restored.

[Problem to be solved by the invention]

In the conventional logical volume implementation methods described above, each of the methods adopted as a countermeasure for the rare case where the mapping information management unit becomes inaccessible has the following drawbacks.

In the duplication method, duplication may occur due to the occurrence of simultaneous failures on different large-capacity file media, even if rare, or the occurrence of a failure on a normal large-capacity file medium while restoring a failed large-capacity file medium. Since access to both mapping information management units may become inaccessible, there is a drawback that it is impossible to deal with such a case.

In addition, in the all-dump method, the contents of the mapping information management section at the time of acquiring all dumps and the contents of the mapping information management section at the time of failure generally do not match, so in order to make both agree, other means, such as acquiring all dumps, are used. There is a drawback that it is necessary to take measures such as logging the subsequent variation information of the mapping information management section and restoring the mapping information management section to a complete state using all dump information and variation information.

In other words, in the conventional logical volume implementation method described above, security measures for such rare cases are incorporated, with consideration given to the rare cases where the mapping information management unit becomes inaccessible during normal processing. It is necessary to keep it.

In view of the above-mentioned points, an object of the present invention is to enable the restoration of the mapping information management section even when access to the mapping information management section becomes impossible due to a failure of a large-capacity file medium, etc., thereby allowing normal processing. The object of the present invention is to provide a logical volume realization method that does not require consideration of rare cases where the mapping information management section becomes inaccessible.

[Means to solve the problem]

The logical volume realization method of the present invention has a logical volume access means, a logical volume management means, and a muffing information management unit, so that a part of a large-capacity file medium can be mapped into one logical volume, and a plurality of large-capacity file media can be mapped. In a method for realizing a logical volume that is displayed as a logical volume, a part of a large-capacity file medium is cut out as a logical volume and a mapping information management section corresponding to the logical volume, and mapping information is stored in this mapping information management section corresponding to the logical volume and the mapping information management section. Logical volume initialization means to be registered;
a logical volume name list collection means for reading a list of logical volume names in a large capacity file medium assigned to a logical volume using a list of large capacity file medium names as key information; and a mapping information management unit restoring means for restoring the mapping information management unit from the mapping information stored in the mapping information management unit corresponding to the logical volume using a list of logical volume names as key information.

[Effect]

In the logical volume realization method of the present invention, the logical volume initial setting means cuts out a part of the large-capacity file medium as a logical volume and a logical volume corresponding mapping information management section, and performs mapping in the logical volume corresponding mapping information management section and mapping information management section. The information is registered, and the logical volume name list collecting means uses the list of large capacity file medium names as key information to read the list of logical volume names in the large capacity file medium assigned to the logical volume, and the mapping information management unit restores the list. uses the list of logical volume names read by the logical volume name list collection means as key information to restore the mapping information management unit from the mapping information stored in the logical volume corresponding mapping information management unit.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a logical volume realization method according to an embodiment of the present invention. Volume access means 2, logical volume management means 3, large capacity file medium 4, logical volume initial setting means 5, mapping information management section 6, mapping information management section restoration means 7, and logical volume name list collection means It consists of 8.

The large-capacity file medium 4 is used as a plurality of logical volumes 41 and a mapping information management section 42 corresponding to logical volumes.

Next, the operation of the logical volume realization method of this embodiment configured as described above will be explained.

When there is a request to create a logical volume 41 specifying a logical volume name from the abdication program 1, the logical volume initial setting means 5 is activated.

The logical volume initial setting means 5 refers to the mapping information of the mapping information management section 6 and sets the large capacity file medium 4.
The real files are extracted from the free space of the logical volume 41 and the logical volume corresponding mapping information management section 42 respectively. Next, the extracted logical volume 41
The mapping information consisting of the real file name of the logical volume 41, the logical volume name of the logical volume 41, the size of the logical volume 41, etc. is registered in the mapping information management section 6, and also registered in the mapping information management section 42 corresponding to the extracted logical volume.

The logical volume initial setting means 5 repeats the above-mentioned initial setting process every time there is a request to create a logical volume 41 specifying a logical volume name from the abdication program l, and completes all the data mapped to the large-capacity file medium 4. A logical volume corresponding mapping information management section 42 is secured corresponding to the logical volume 41, and mapping information is registered in the secured logical volume corresponding mapping information management section 42 and mapping information management section 6.

When the plurality of logical volumes 41 and the logical volume corresponding mapping information management unit 42 are initialized in the large-capacity file medium 4 in this way, the large-capacity file medium 4
is in a state where it is used as a plurality of logical volumes 41.

In normal processing, when the abduction program 1 accesses the logical volume 41 by specifying the logical volume name, the logical volume access means 2. Since this is done via the logical volume management means 3 and the mapping information management section 6, the appearance of the logical volume 41 to the ablation program I is exactly the same as in the past.

That is, when there is an access request specifying a logical volume name from an application program 1, the logical volume access means 2 uses the logical volume management means 3 to refer to the mapping information in the mapping information management section 6 and determine the real file name such as the real file name. The information is obtained and the corresponding logical volume 41 is accessed.

Note that when there is a request to delete a logical volume 41 specifying a logical volume name from the abbling program 1, the logical volume access means 2 uses the logical volume management means 3 to delete the corresponding mapping from the mapping information management section 6. Delete information. At this time, it is not necessarily necessary to delete the corresponding logical volume 41 and logical volume correspondence mapping information management section 42 on the large-capacity file medium 4.

Next, a mapping information management unit 6 is provided, and the mapping information management unit 6 is used when access to the mapping information management unit 6 becomes impossible due to a failure of the large-capacity file medium 4, etc.
This section explains how to restore the .

First, a list of large capacity file media names assigned to the logical volume 41 is obtained. The list of large file media names assigned to the logical volume 41 is generally managed by the mapping information management unit 6, so in a situation where it is impossible to access the mapping information management unit 6, similar information may be managed separately. For example, the logical volume 4 is retrieved from the document of the mapping information management unit 6, etc.
It is necessary to obtain a list of large capacity file media names assigned to 1.

When the list of large-capacity file medium names assigned to the logical volume 41 is known, the mapping information management unit restoration means 7 restores the large-capacity file medium names in the list of large-capacity file medium names assigned to the logical volume 41. Using this as key information, the logical volume name list collecting means 8 refers to the logical volume correspondence mapping information management unit 42 corresponding to each logical volume 41 in the large capacity file medium 4 specified by the large capacity file medium name, and collects the logical volume name. Get a list of.

Next, the mapping information management unit restoring means 7 reads the mapping information of the logical volume mapping information management unit 42 corresponding to each logical volume 41 using the logical volume name in the list of logical volume names as key information, and restores the new size. The information is sequentially written to the mapping information management section 6 provided in the capacity file medium 4 or the large capacity file medium 4 from which the failure has been removed.

When the processing for all the logical volumes 41 in one large-capacity file medium 4 is completed, the mapping information management unit restoration means 7 performs the same process for the other large-capacity file mediums 4 assigned to the logical volume 41. Perform processing.

As a result of the above processing, the mapping information management unit 6 in the latest state
is restored.

〔Effect of the invention〕

As explained above, in the rare case where the mapping information management unit becomes inaccessible, the present invention manages the mapping information in the latest state from the logical volume mapping information management unit provided corresponding to each logical volume. By making it possible to restore the mapping information management section, there is an effect that there is no need to be aware of rare cases such as inaccessibility of the mapping information management section during normal processing.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a logical volume implementation method according to an embodiment of the present invention. In the figure, l... Abbreviation program, 2... Logical volume access means, 3... Logical volume management means, 4... Large capacity file medium, 5... Logical volume initial setting means, 6... Mapping information management unit, 7... Mapping information management unit restoration means, 8... Logical volume name list collection means, 41... Logical volume, 42... Logical volume corresponding mapping information management unit. be.

Claims (1)

[Claims] By having a logical volume access means, a logical volume management means, and a mapping information management unit, a part of a large-capacity file medium can be mapped into one logical volume, and a large-capacity file medium can be mapped into a plurality of logical volumes. In a method for realizing a logical volume that is displayed as a volume, a logic that extracts a part of a large-capacity file medium as a logical volume and a logical volume corresponding mapping information management section and registers mapping information in this logical volume corresponding mapping information management section and the mapping information management section is provided. a volume initialization means; a logical volume name list collection means for reading a list of logical volume names in a large capacity file medium assigned to a logical volume using a list of large capacity file medium names as key information; and this logical volume name list. mapping information management unit restoration means for restoring the mapping information management unit from mapping information stored in the logical volume corresponding mapping information management unit using a list of logical volume names read by the collection unit as key information; Characteristic logical volume realization method.