JPH11327792A - Disk device and its dynamic capacity increasing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dynamic capacity increasing method of a disk device capable of being replaced with a disk device with larger capacity as making data stored in the disk device accessible. SOLUTION: The method is constituted by providing a step to copy the stored data in a first disk device 10 in a second disk device 20, a step to make access to the first disk device 10 when reading is requested during copy of the stored data and to make access to the first and the second disk devices 10, 20 when writing is requested, a step to record a list of position information of a management information area 22 of the second disk device 20 in a specified place of the second disk device 20 and to manage a data area 21 of the second disk device 20 based on the list and a step to generate the management information for an unrecognized area 23 on the second disk device 20 and to define the unrecognized area 23 as the data area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for dynamically increasing the capacity of a disk device for recording data as a storage device of an information processing device.

[0002]

2. Description of the Related Art An information processing apparatus such as a computer has a disk device capable of storing a large amount of data as a storage device. If data is accumulated in this disk device one after another and the storage capacity becomes insufficient, it is necessary to increase the capacity of the disk device. In general, as a method of increasing the capacity of a disk device, a method of replacing the disk device itself with one having a larger capacity is adopted.

More specifically, access to a small-capacity disk device that has run out of storage capacity is temporarily stopped,
All data stored in the disk device is copied to a large-capacity disk device for each file. The copy of the stored data may be performed using a magnetic tape as a medium. After the copying of the stored data is completed, the small-capacity disk device is replaced with a large-capacity disk device from which the stored data has been copied, and data access is resumed.

[0004]

However, according to the above-mentioned method for increasing the capacity of the disk device, access to the disk device is stopped during the replacement operation of the disk device. Has a problem that the processing is interrupted.

The present invention has been made in view of such circumstances, and provides a method for dynamically increasing the capacity of a disk device, which allows access to the disk device while increasing the capacity of the disk device. The task is to

[0006]

A method of dynamically increasing the capacity of a disk device according to the present invention has the following arrangement to achieve the above object. That is, the present invention has a data area for storing a data body and a management information area in which management information of the data area is stored on a disk as a recording medium, and refers to the management information. A method for dynamically increasing the capacity of a disk device that accesses the data area, comprising: (a) storing data stored in a first disk device in a second storage device having a larger capacity than the first disk device;
And (b) when the read request is issued during the copying of the storage data, the first
Accessing the first and second disk devices when there is a write request during the copying of the storage data; and (c) at a specific location of the second disk device. Recording the position of the management information area of the second disk device as a list, and managing the data area of the second disk device based on the list; Generating management information for the recognized area and setting the unrecognized area as a data area.

According to this method, the same data as in the first disk device is stored in the second disk device by copying the storage data from the first disk device to the second disk device. By accessing the first disk device when a read request is made during the copying, and accessing the first disk device and the second disk device when a write request is made, data can be copied during the copying. Even if accessed, the storage data of the first disk device and the second disk device are the same. Therefore, the stored data is copied from the first disk device to the second disk device in a state where the data can be accessed. Subsequently, a list of management information areas of the second disk device is created, and this data area is managed, so that the second disk device is managed instead of the first disk device. Subsequently, management information for an unrecognized area on the second disk device is generated, and the unrecognized area is used as a data area, thereby expanding the data area of the second disk device.
As described above, the first disk device is replaced with the second disk device without interruption of access.

[0008] The step of setting the unrecognized area as a data area may include, for example, adding the unrecognized area to an unused data area in management information stored in a management information area of the second disk device. Is added. Thereby, the unrecognized area of the second disk device is added to the data area, and the data area of the second disk device is enlarged.

Further, the step of setting the unrecognized area as a data area includes, for example, adding a part of the unrecognized area to the list as a new management information area, and adding the rest of the unrecognized area to a new data area. Is generated and stored in the new management information area. As a result, a new data area is generated in the second disk device, and the data area of the second disk device is expanded.

Still further, the disk device according to the present invention has a data area for storing a data body on a disk as a recording medium, a management information area in which management information of the data area is stored; A list in which position information of the information area is recorded, and accessing the data area by referring to management information stored in the management information area based on the list.

According to this apparatus, a management information area is provided for the data area, management information for managing the data area is stored in the management information area, and the position information of the management information area is listed. Be recorded. When accessing the data area, the position of the management information area is specified based on the list, and the management information stored in this management information area is read. Then, the data area is accessed based on the position of the data area specified by the management information. Therefore, it is possible to access the data area expanded by the above method.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, referring to the drawings, a small capacity disk device is replaced with a large capacity disk device.
An embodiment of the present invention will be described for a case where the capacity of a disk device is increased. In the drawings, common elements are denoted by the same reference numerals.

Embodiment 1 FIG. In the method for increasing the capacity according to the first embodiment of the present invention, data is copied from a small-capacity disk device to a large-capacity disk device by using a recording method called “duplication of data” together. And
By adding the unrecognized area of the large-capacity disk device to the data area as an unused area, the data area is enlarged to increase the capacity.

FIG. 1 shows the concept of a method for dynamically increasing the capacity of a disk device according to the first embodiment of the present invention. The small-capacity disk device 10 shown on the left side of FIG. 1 is a disk device before a large-capacity storage (before replacement). And a management information area 12 stored therein. The management information includes information such as a file name of data stored in the data area 11, a recording position of each file, or a leading physical address indicating a position of an unused data area (empty area).

The large-capacity disk device 20 shown in the center of FIG. 1 is in the middle of increasing capacity (replacement process), and has a data area 21 for storing data itself,
It has a management information area 22 in which management information for managing the data area 21 is stored, and an unrecognized area 23 that is not recognized as a data area. The large-capacity disk device 20 shown on the right side of the drawing has been subjected to a large capacity (after replacement), and includes a data area 24 for storing a data body,
And a management information area 22 in which management information for managing the data area 24 is stored. Although not shown in FIG. 1, a list in which information for managing the position of the management information area is stored in a specific location of the disk device 20.

Hereinafter, a method for dynamically increasing the capacity of a disk device according to the first embodiment will be described in detail with reference to the flowcharts shown in FIGS. First, a process (dynamic device replacement process) for replacing the disk device 10 with the disk device 20 is performed. That is, the access method for the disk devices 10 and 20 is set to a recording method called duplication of disks, which will be described later, and all storage data in the data area 11 and the management information area 12 of the disk device 10 are copied to the disk device 20. (Step S10), a data area 21 and a management information area 22 are created on the disk device 20. An area other than the data area 21 and the management information area 22 is an unrecognized area 23.

Here, a recording method called disk duplication will be described. Usually, this recording method is a recording method used to prevent data loss due to a failure of a disk device, and the same data is recorded on two disk devices. If this recording method is used in combination, the access to the disk device by the external information processing device (not shown) can be continued during the copying from the disk device 10 to the disk device 20, and the data can be accessed without interruption. Can be copied.

A method of copying data using a recording method called duplication of the disk will be described in detail. First, the data read from the physical address X on the disk device 10 is replaced with the same physical address X on the disk device 20.
And the data of each physical address is sequentially copied.
Here, during the copying period from the start to the end of copying (during copying)
When an external information processing device reads data, the disk device 10 is accessed and desired data is read from the disk device 10. When an external information processing device writes data during this copying period, both the disk device 10 and the disk device 20 are accessed, and the same data is written to these same physical addresses. Thus, the data area 11 of the disk device 10 can be stored without stopping external access to the disk device.
All the data in the management information area 12 are copied to the data area 21 and the management information area 22 of the disk device 20, respectively.

Next, when the copying of the data using the above-described recording method based on the duplexing of the disk is completed, the position information of the management information area 22 (for example, the starting physical address and the size of the area) is stored in a specific location of the disk device 20. Is created, and the data area of the disk device 20 is managed based on the list (step S11). As described above, the management target moves from the disk device 10 to the disk device 20, and the disk device is dynamically replaced (dynamic device replacement processing ends).

Next, the unrecognized area 23 of the disk device 20
Is performed as a data area (area enlargement processing). That is, information that sets the unrecognized area 23 as an unused data area (hereinafter, referred to as “free area information”) is generated and added to the management information stored in the management information area 22 (step S12). Specifically, the position information (for example, the top physical address and the size of the area) of the unrecognized area 23 is added to the management information stored in the management information area 22 as free area information. As a result, the unused area of the data area 21 increases, and the data area 21 is expanded to the data area 24 (the area expansion processing ends). However, since the amount of information stored in the management information area increases as the number of unused areas increases, a sufficient spare area is provided in the list of management information areas from the beginning. As described above, the disk device 10 is replaced with the disk device 20, and its data area is enlarged to increase the capacity.

In the disk device 20 having a large capacity according to the first embodiment, a data area 21 for storing a data body and respective management information of the data area are stored on a disk as a recording medium. Management information area 22;
And a list in which the position information of the management information area is recorded. When accessing a file stored in the data area 21 of the disk device 20, first, the position of the management information area 22 is specified based on the list. Next, the management information stored in the management information area 22 is read, and the position of a desired file stored in the data area 21 is specified. If the location of this file can be specified, access to this file becomes possible.

According to the first embodiment, the data area is enlarged by adding free area information that makes the unrecognized area an unused area to the existing management information area, so that the size of the list of management information areas is reduced. The data area can be expanded without increasing, and there is no need to provide a spare area in the list of management information areas.

Embodiment 2 FIG. Next, a second embodiment according to the present invention will be described. In the first embodiment, the data area is expanded by adding free area information to the management information stored in the management information area 22. However, the data area is increased to store more data than before. When it becomes possible, the management information area may be insufficient. Therefore, in the second embodiment, the management information area and the data area are newly created in the unrecognized area 23 to enlarge the data area, thereby avoiding the shortage of the management information area due to the increase in the data amount.

FIG. 3 shows a concept of a method for dynamically increasing the capacity of a disk device according to a second embodiment of the present invention. The small-capacity disk device 10 shown on the left side of FIG. 1 is the one before the increase in capacity (before replacement), and has a data area 11
Having. Also, the disk device 20 shown in the center of FIG.
This is a process in the middle of increasing the capacity (replacement process), and has a data area 21, a management information area 22, and an unrecognized area 23. Further, the disk device 20 shown on the right side of the figure has a large capacity (after replacement), and has data areas 21 and 24.
And management information areas 22 and 25 storing management information for managing these data areas 21 and 24, respectively. Although omitted in FIG. 2, the disk device 2
A list in which information for managing the positions of the plurality of management information areas is stored in the specific location 0.

Hereinafter, the method for increasing the capacity according to the second embodiment will be described with reference to the flowcharts shown in FIGS. First, a process (dynamic device replacement process) for replacing the disk device 10 with the disk device 20 is performed. That is, as shown in the center of FIG. 3, data is copied from the disk device 10 to the disk device 20 by using the recording method based on the duplication of the disk, as in the first embodiment, and the data is stored on the disk device 20. An area 21 and a management information area 22 are created (step S20). An area other than the data area 21 and the management information area 22 is an unrecognized area 23.

Subsequently, a list (not shown) for recording the position information (for example, the starting physical address and the area size) of a plurality of management information areas including the management information area 22 at a specific location on the disk device 20. ) Is created, and each data area is managed based on this list (step S21). As a result, the management target moves from the disk device 10 to the disk device 20, and the disk device is dynamically replaced (dynamic device replacement processing ends).

Next, the unrecognized area 23 of the disk device 20
First, a management information area and a data area are newly created, and processing (area enlargement processing) for using the unrecognized area 23 as a data area is performed. That is, a part of the unrecognized area 23 is added to the list as a new management information area 26. Specifically, the position information of the management information area 26 is added to the management information area list (step S22).

Subsequently, management information for generating the rest of the unrecognized area 23 as a new data area 25 is generated and stored in the management information area 25. Specifically, the position information of the unrecognized area 23 (for example, the head physical address and its size) is stored as management information (step S23). As a result, a data area 25 is newly added, and the disk device 20 is added.
Is enlarged (the area enlargement process ends).

The data areas 21 and 25 of the disk device 20 are managed by management information stored in management information areas 22 and 26, respectively.
It is centrally managed by the above list. As described above, the disk device 10 is replaced with the disk device 20, and the capacity of the disk device is increased.

FIG. 5 shows an example of the address space on the disk device 20 after the increase in capacity and its data structure. In this example, the head address space (specific location) of the disk device 20 is allocated to the management information area list 200 described above. The next address space is assigned to the management information area 22 and the data area 21, and the next address space is assigned to the management information area 26 and the data area 25. The address space allocated to the management information area list 200 is not limited to the first address space.
Other address spaces may be used.

The disk device 20 having a large capacity according to the second embodiment has a plurality of data areas 21 and 25 for storing data bodies on a disk as a recording medium.
A plurality of management information areas 22 and 26 storing respective management information of the data area;
And a list 200 in which the position information of No. 6 is recorded. For example, when accessing a file stored in the data area 21 of the disk device 20, first, the management information area 22 of the data area 21 storing the file is searched based on the list 200, and the management information area 22 of the management information area 22 is searched. Identify the location. Next, the management information stored in the management information area 22 is read, and the position of a desired file stored in the data area 21 is specified. If the location of this file can be specified, access to this file becomes possible.

According to the second embodiment, the unrecognized area 2
3, a new management information area 26 is provided, and the data area is expanded by adding it to the list of management information areas. Therefore, the data area can be expanded without increasing the amount of information stored in each management information area. It is not necessary to provide a spare area in each management information area.

In the second embodiment, the data areas 21 and 25 are generated in the disk device 20.
More data areas may be generated. In this case, a management information area may be provided for each data area, and the management information of each data area may be stored in each management information area.
However, if the number of data areas is increased, the number of management information areas is increased, and the amount of information stored in the management information area list for managing this is also increased. A spare area is provided in advance.

The first embodiment and the second embodiment may be combined. For example, a data area is sequentially expanded by adding free area information to management information of a certain management information area, and when this management information area becomes full, a new management information area is generated and added to the list. With this configuration, each management information area can be effectively used, and the number of data areas and management information areas can be minimized.

[0035]

As is apparent from the above description, according to the present invention, the following effects can be obtained. That is, according to the method according to the first aspect of the present invention, data stored in the disk device is copied to a larger one, and the unrecognized area of the disk device in which the data is copied is copied to the data area. Is generated, the data area can be expanded by replacing the disk device with a disk device having a larger capacity without interrupting access to the disk device.

According to the method of the present invention, the management information of the data area is rewritten to extend this data area, so that the size of the list of management information areas can be increased. And the data area can be expanded.

Further, according to the method of the present invention, a new management information area is added to the list of management information areas to generate a new data area. The data area can be expanded without increasing the amount of management information stored in the area.

Further, according to the apparatus of the present invention, a data area on a disk, a management information area storing management information for managing the data area, and a management information area Since there is provided a list in which the position information of the areas is recorded, one or more data areas can be accessed based on the list.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a method of dynamically increasing the capacity of a disk device according to a first embodiment of the present invention;

FIG. 2 is a flowchart for explaining a method of dynamically increasing the capacity of the disk device according to the first embodiment of the present invention;

FIG. 3 is a diagram for explaining a method of dynamically increasing the capacity of a disk device according to a second embodiment of the present invention;

FIG. 4 is a flowchart for explaining a method for dynamically increasing the capacity of a disk device according to a second embodiment of the present invention;

FIG. 5 is a diagram for explaining a detailed data structure of the disk device according to the second embodiment of the present invention;

[Explanation of symbols]

10... Small capacity disk devices, 11, 21, 24, 25
... data area, 12, 22, 26 ... management information area, 20
... large-capacity disk device, 23 ... unrecognized area, 200 ...
List of management information areas.

Claims (4)

[Claims] A data area for storing a data body on a disk as a recording medium; and a management information area in which management information of the data area is stored. A method for dynamically increasing the capacity of a disk device that accesses a data area, comprising: (a) copying data stored in a first disk device to a second disk device having a larger capacity than the first disk device; (B) accessing the first disk device when there is a read request during the copying of the storage data, and accessing the first disk device when there is a writing request during the copying of the storage data.
And accessing the second disk device; and (c) storing the second disk device in a specific location of the second disk device.
Recording the position of the management information area of the disk device as a list, and managing the data area of the second disk device based on the list; and (d) controlling the unrecognized area on the second disk device. Generating management information and setting the unrecognized area as a data area. 2. The method according to claim 1, wherein the step of setting the unrecognized area as a data area includes adding information that sets the unrecognized area to an unused data area to management information stored in a management information area of the second disk device. 2. The method according to claim 1, wherein the capacity of the disk device is dynamically increased. 3. The step of setting the unrecognized area as a data area, adding a part of the unrecognized area to the list as a new management information area, and setting the rest of the unrecognized area as a new data area. 2. The method according to claim 1, wherein management information is generated and stored in the new management information area. 4. A data area for storing a data body, a management information area in which management information of the data area is stored, and position information of the management information area are recorded on a disk as a recording medium. A disk device, comprising: a list; and accessing the data area by referring to management information stored in the management information area based on the list.