JPH05143405A - File allocation system - Google Patents

Abstract

PURPOSE:To prevent file access performance from being lowered and to reduce the number of times for a user to secure a file area again in order to cancel the division of the file area by reducing area division to be generated when frequently securing, opening and extending the file area to a magnetic disk medium. CONSTITUTION:When initializing a magnetic disk medium 11, a logical area setting means 13 divides the storage area of the magnetic disk medium 11 into logical areas and prepares a logical area use condition table 12 showing the use conditions of the respective logical areas. When securing the file area, the file area is secured in the logical area in an unused state by referring to the logical area use condition table 12. In this case, when the file area is secured, it is secured for the unit of plural continuous cylinders and therefore, even when the file is frequently secured and opened or even when the file area is frequently extended automatically by a system, the frequency of the file area division can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file allocation method for a magnetic disk medium, and more particularly to a file allocation method for logically dividing a storage area of a magnetic disk medium and securing a file area for each logical area unit. ..

[0002]

2. Description of the Related Art Conventionally, when a user secures a file area on a magnetic disk medium, the area is used from the smaller cylinder number of the magnetic disk medium, so that the magnetic disk after securing a plurality of file areas. Have file areas of different sizes adjacent to each other.

Therefore, when the file area is automatically expanded by the operating system, the expansion may not be performed in an adjacent area, and a file that is physically reserved in an area is logically allocated. It becomes necessary to handle it as one file.

Further, in the magnetic disk medium in which the file area is frequently reserved and released, as described above,
This means that there are many files whose areas are divided into multiple parts.

When a large number of files whose areas are divided into a plurality of areas are present on a magnetic disk, the user once saves the file to a storage medium such as a magnetic tape, deletes the file from the magnetic disk, or deletes the magnetic disk. After initializing, the file area is secured again and the file contents are restored from the saved medium to the magnetic disk medium to eliminate the file area division.

[0006]

As described above, a magnetic disk medium that frequently reserves, releases, and expands a file area is logically one file, but the area is divided and physically There will be many files that are secured at distant positions.

Therefore, conventionally, when accessing each file of the magnetic disk medium in which a large number of files whose areas are divided exist, the movement of the read / write head of the magnetic disk becomes large and the access performance deteriorates. There was a point.

Further, the number of area divisions of one file is limited, and there are cases where re-expansion becomes impossible due to excessive division. Therefore, the user needs to reallocate the file area of the magnetic disk again at an arbitrary point in time, and there is also a problem that this work takes a lot of time.

In view of the above-mentioned drawbacks, the technical problem of the present invention is to provide an unsecured area between each of the files to be secured when the file area is secured, and to contiguously when the file area is expanded. Use the existing unallocated space,
The object of the present invention is to provide a file allocation method for preventing a decrease in file access performance and reducing the number of times of reallocating a file area of a magnetic disk by reducing the frequency of area division.

[0010]

According to the present invention, in the file allocation method utilizing the function of expanding the area of a file secured on a magnetic disk medium, the storage area of the magnetic disk medium is divided into a plurality of consecutive cylinders. A logical area usage table for dividing and recording the usage status of the divided areas, a logical area setting means for creating the logical area usage table at the time of initialization of the magnetic disk medium, and the magnetic disk medium When allocating a file area, the logical area allocating means for deciding a position for allocating the area by referring to the logical area usage status table and updating the logical area usage status table, and the file area are released. In this case, a logical area releasing means for updating the logical area use status table is included. Allocation method can be obtained.

That is, according to the file allocation method of the present invention, a user in a system utilizing a function of automatically expanding the area when the area of the file secured by the user on the magnetic disk medium is insufficient. In the magnetic disk medium with a large number of files that frequently reserve the file area and the frequency with which the area is automatically expanded, the storage area of the magnetic disk medium is divided into a plurality of consecutive cylinders. Logical area usage status table that records the usage status of the specified area, logical area setting means that creates the logical area usage status table when the magnetic disk medium is initialized, and the user secures a file area on the magnetic disk medium When you do so, refer to the logical area usage table to determine the position to secure the area, and A logical space allocation means for updating the usage table, when the user opens the file area, and a logic region releasing means for updating the logical space usage table.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

File allocation method 1 of this embodiment
Is connected to the magnetic disk medium 11, the magnetic disk medium initializing means 16, the file area securing means 17, and the file area releasing means 18, and the logical area use status table 12 and the logical area setting means 13 are connected. , And a logical area allocating means 14 and a logical area releasing means 15.

The magnetic disk medium 11 is a storage medium in which the user arbitrarily initializes the medium and secures and releases the file area.

The logical area use status table 12 stores the storage area of the magnetic disk medium 11 as a logical area of a plurality of consecutive cylinders, and stores the use status of the logical area as a used or unused state. It is referred to when allocating and freeing an area.

When the magnetic disk medium 11 is initialized by the magnetic disk medium initialization means 16, the logical area setting means 13 sets all usage status flags in the logical area usage status table 12 indicating whether or not the logical area is used. It is set in an unused state and stored in a specific position on the magnetic disk medium 11.

When the medium is initialized, the user specifies the size of the logical area in the magnetic disk medium initializing means 16, and the logical area setting means 13 specifies the size of the specified logical area. The storage area of the magnetic disk is divided into two, and the logical area usage status table 12 is created.

In the logical area allocating means 14, the user uses the file area securing means 17 to make the magnetic disk medium 11
When reserving a file area, the logical area use status table 12 is referred to, and a logical area in which the flag indicating the use status of the logical area is in the unused state is allocated as the user's file area.

After the allocation, the flag in the unused state is changed to the used state, and the logical area use status table 12 is stored in the magnetic disk medium 11.

The logical area releasing means 15 refers to the logical area use status table 12 when the user releases the file area secured in the magnetic disk medium 11, and refers to the logical area used by the released file. The flag indicating the usage status of the logical area is changed to the unused status, and the logical area usage status table 12 is stored in the magnetic disk medium 11.

The magnetic disk medium initialization means 16 deletes the files and data stored in the storage area of the magnetic disk medium 11, and after initialization, the logical area setting means 1
3 is requested to request the creation of the logical area usage status table 12.

When the user requests the magnetic disk medium 11 to allocate a file, the file area reserving means 17 passes the allocated size to the logical area allocating means 14 to request the allocation of the logical area.

After that, the physical area of the allocated logical area is obtained from the logical area allocation means 14 and the file area is allocated.

The file area releasing means 18 releases the file area when the user requests the release of the area for the file secured in the magnetic disk medium 11 and then determines the physical position of the released area. Logical area releasing means 1
5 is requested to request the release of the logical area.

FIG. 2 shows the configuration of the logical area use status table 12 and the logical area use status table 12 shown in FIG.
FIG. 3 is a diagram showing the relationship between the logical areas of the magnetic disk medium 11 and the magnetic disk medium 11.

In FIG. 2, the logical area usage status table 21 corresponds to the logical area usage status table 12 in FIG. 1, and the magnetic disk 25 corresponds to the magnetic disk medium 11 in FIG.

The logical area usage status table 21 is composed of a logical area number 22, a magnetic disk physical position 23 corresponding to the logical area, and a logical area usage status flag 24, and is stored in the magnetic disk 25. It

The magnetic disk 2 is assigned to the logical area number 22.
Serial numbers are assigned in ascending order from 1 to the logical areas divided at the time of initialization of 5.

The physical position 23 stores the start position and the end position of the magnetic disk assigned to each of the divided logical areas.

In the logical area usage status flag 24, the usage status of the logical area is stored as one of two statuses, used and unused.

Next, the file allocation method of the present embodiment configured as shown in FIG. 1 will be described in the order of initialization of the magnetic disk medium 11, securing of the file area, and release of the file area.

When the magnetic disk medium 11 is initialized, the magnetic disk medium initializing means 16 initializes the logical area use status table 12 by the logical area setting means 13 together with the conventional initialization processing.

Initialization of the logical area usage table 12 is performed by first dividing the logical area. The size of the logical area is specified by the user when the magnetic disk medium 11 is initialized.

The logical area setting means 13 divides the storage area of the magnetic disk by the size of the logical area specified by the user, and the start position and the final position of the divided logical area are stored in the physical area of the logical area use state table 12. The flag is stored in the storage area at the position 23, and the logical area use status flag 24 is set to the unused state.

The logical area setting means 13 stores the physical position 23 of the logical area and the logical area usage flag 24 for all the divided logical areas, and then writes the logical area usage table 12 to the magnetic disk medium 11. ..

When the user reserves the file area on the magnetic disk medium 11, the file area securing means 17 performs the logical area allocating means 1 before the conventional file area securing.
4 is required to determine the logical area to be secured.

The logical area allocating means 14 obtains the number of logical areas from the size of the file designated by the user when allocating the file. For example, when the size of the logical area is set to 10 cylinders and the file area of 5 cylinders is secured when the magnetic disk medium 11 is initialized, the required logical area is 1 and the file area of 15 cylinders is set. When securing, it is determined that the required logical area is two.

Next, the logical area allocating means 14 checks whether or not the required number of logical areas can be secured by referring to the logical area usage status table 12.

The logical area allocating means 14 selects a logical area in which the usage status flag of the logical area usage status table 12 is in an unused state.

Next, the logical area allocating means 14 obtains the physical position of the magnetic disk medium 11 with respect to the selected logical area by referring to the value of the physical position 23 of the logical area usage status table 12, and then the file area. Securing means 1
7, and the file area securing means 17 secures the file area.

After the file area is secured, the file area securing means 17 changes the usage status flag 24 of the logical area corresponding to the used logical area to the usage status,
The logical area usage table 12 is stored in the magnetic disk medium 11
To store.

When the area secured by the file area securing means 17 is smaller than the logical area, the difference between the size of the logical area and the size of the file area becomes an unused area,
After that, when it becomes necessary to expand the file, it is possible to expand adjacently depending on the size of the logical area, and the frequency of dividing the file area can be suppressed.

For example, when the logical area usage table 12 is created with the size of the logical area being 10 cylinders and a file of 5 cylinders is secured, the extension up to the remaining 5 cylinders can be secured in the adjacent area.

When a file of 13 cylinders is secured, two logical areas are needed, but adjacent areas can be secured up to the remaining 7 cylinders of the second logical area.

Here, in the case of the file described later, the expansion of the 8th cylinder means that an additional logical area is secured,
After the allocation, it can be expanded adjacently up to 10 cylinders, which is the size of the third logical area.

When the user releases the file area, after the file area releasing means 18 releases the file area,
The logical area releasing means 15 is notified of the physical position of the magnetic disk medium 11 in which the area of the file is secured.

The logical area releasing means 15 searches the logical area use status table 12 for a physical position that matches the notified physical position of the magnetic disk medium 11 and obtains a corresponding logical area.

The logical area releasing means 15 changes the logical area use status flag 24 corresponding to the obtained logical area to an unused state, and stores the logical area use status table 12 in the magnetic disk medium 11.

The unused logical area can be secured by the file area securing means 17 when the file area is secured next time.

[0051]

As described above, according to the present invention, when a file area is secured for a magnetic disk medium,
Files are secured in units of multiple consecutive cylinders, not in units of magnetic disk cylinders, so even if files are frequently reserved and released, or even if the system automatically expands the file area frequently, It is possible to reduce the frequency of dividing the area,
This has the effect of preventing a decrease in file access performance.

Further, since the frequency of dividing the file area is reduced, there is an effect that the number of user's work such as releasing and reallocating the area of the divided file is reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a logical area use status table 12 in FIG.
3 is a diagram showing the relationship between the logical area usage state table 12 and the logical area of the magnetic disk medium 11 of FIG.

[Explanation of symbols]

 11 magnetic disk medium 12 logical area use status table 13 logical area setting means 14 logical area allocating means 15 logical area releasing means 16 magnetic disk medium initializing means 17 file area securing means 18 file area releasing means 21 logical area use status table 25 magnetic disk

Claims (1)

[Claims] 1. A file allocation method utilizing a function of expanding a file area secured on a magnetic disk medium, wherein a storage area of the magnetic disk medium is divided into a plurality of continuous cylinders, and the divided areas are used. A logical area usage status table for recording the status; a logical area setting means for creating the logical area usage status table at the time of initialization of the magnetic disk medium; and a logical area setting means for securing a file area on the magnetic disk medium. A logical area allocating unit that refers to the area usage status table to determine the position to secure the area and updates the logical area usage status table; and, when the file area is released, stores the logical area usage status table. A file allocation method including a logical area releasing means for updating.