JP3033736B2 - Remote disk unit access system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote disk device access system configured to execute an application program on a terminal-side computer using a remote disk device connected via a network as a storage device. More specifically, the present invention relates to a remote disk device access system in which a local disk device is connected to a computer on a terminal side, and processing speed is improved by writing and reading data to and from this local disk device in block units. It is.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 6-290090 describes a remote file access system for improving the efficiency and cost of accessing disk devices connected via a wide area network. I have. This remote file access system is configured as follows. A remote file server and a user-side device are connected by a wide area network. On the user side, a plurality of portable computers are connected by a local area network, and further connected to a wide area network via a base unit information communication control device.
The child device information communication control device connected to the portable computer has a primary cache, and the master device information communication control device has a large-capacity secondary cache.

The primary cache stores a copy of data that is currently being accessed to a disk device provided in a file server. The primary cache is constituted by a high-speed and small-capacity storage medium such as a memory. The primary cache directory has an entry corresponding to the block of the primary cache, and stores a block address on the disk device. The secondary cache is a large-capacity storage medium such as a disk device, and is divided into specific block units. The secondary cache stores a copy of the data of the disk device of the file server accessed in the past by the portable computer connected to the local area network managed by the parent device information communication control device. The secondary cache directory has an entry corresponding to the block of the secondary cache, and stores the block address on the disk device.

Japanese Patent Application Laid-Open No. Hei 9-288677 can provide the latest information, does not require a long time to acquire information even if the acquired information includes image (moving image) information, and reduces the load on the network. An information integrated display method, apparatus, and integrated display system which enable editing and display in which information owned by a user terminal itself and information held by a server are organically combined are described. This information integrated display method, apparatus and integrated display system are provided by WWW (World Wide Network).
Web) In order to centrally display, on a display device of a client terminal, document information that is updated from time to time, which is obtained from a server via the Internet, and document information that is not updated and individually stored on a client terminal side. The location of each piece of information constituting the display content is described in a common page description language (HTML), and the document information acquired from the WWW server using a browser (WWW browser) and the document information held in the client terminal side Are displayed in the same display area of the display device.

[0005]

Problems to be Solved by the Invention
In the remote file access system described in Japanese Patent Application Publication No. 0-200, a portable computer as a terminal is provided with a primary cache composed of a high-speed and small-capacity storage medium, and is connected to the portable computer via a local area network. Since the master unit information communication control device is provided with the secondary cache constituted by a large-capacity storage medium such as a disk device, the data capacity that can be stored in the primary cache directly connected to the portable computer is limited. with limited Ru <br/> that, when the load of the local area network is high it takes time to access the second cache comprising a large-capacity disk unit, etc., can not be utilized effectively second cache large capacity There is.

Conventionally, as described in Japanese Patent Application Laid-Open No. 9-288677, data stored in a remote disk device of another (host or server) computer connected via a network is read. When writing data to a remote disk device, copy the target file to a local disk device directly connected to the computer (terminal), and then write and read data to and from the copied file. Address the fact that the data write / read processing speed is affected by the load state of the network.

However, in the method of copying data in file units, unnecessary data portions may be read into the local disk device, and the local disk device having a limited storage capacity may not be used effectively.

The present invention has been made to solve such a problem, and uses a local disk device directly connected to a terminal computer as a temporary data storage unit.
By managing local disk units in blocks, it is possible to effectively use local disk units with limited storage capacity, improve the data write / read processing speed, and improve network performance even when the network load is high. It is an object of the present invention to provide a remote disk device access system which enables stable and high-speed access to a remote disk device connected via the remote disk device.

[0009]

According to a first aspect of the present invention, there is provided a remote disk device access system which is connected via a network and comprises a fixed length block.
The remote disk device having a divided storage area used as a storage device, the remote disk device access system configured to execute an application program on the terminal side of the computer, the remote
Divided into blocks of the same size as
A storage area, with local disk device used as a temporary storage area of data to the terminal side of the computer, the terminal computer reads the request data to the remote disk device from said application program And data read from the remote disk device in response to a write request or
Stores the data to be written in the remote
Corresponding to the block in the
Stored in a block in the local disk device,
At this time, the remote directory is added to the block to be stored.
If write data for the disk device has already been stored
If the write data is
Write to a block in the smart disk device .

[0010]

The terminal-side computer has a data read processing unit, and the local disk device has a block management table and a block to be invalidated first.
Free list start block containing information indicating the lock
Comprising a click information storage unit, the data reading processing unit, to the read request of data stored in the remote disk device from said application program, searches the block management table, the request data is stored
Block corresponding to the block in the remote disk device
When the lock exists in the local disk device
, The A reads the requested data from the block
Pass the application program, the request data is stored
Corresponding to the block in the remote disk device
Block does not exist in the local disk device
If, wherein via the network from the remote disk device to read out the requested data Apurikeshi
Transfer the request data to the
Information stored in the free list start block information storage
In the local disk device specified by
The remote disk where the request data was stored
It is configured to be stored in association with the block of the backup device .

Further, the computer on the terminal side is provided with a data write processing unit, and the local disk device is invalidated first with a block management table .
Free list start block storing information indicating blocks
A data write processing unit that searches for a block management table in response to a data write request to a remote disk device from an application program, and writes the requested data.
Block corresponding to the block in the remote disk device
Is present in the local disk device,
Run the overwrite processing for the block of data, the request
In the remote disk unit where data is to be written
The block corresponding to the block
If the request data does not exist in the
To the information stored in the lead list start block information storage
Block specified in the local disk device
Stored in

By arranging the block management table on the memory of the computer on the terminal side, the block management may be performed at a high speed.

In the remote disk device access system according to the present invention, the local disk device is used as a temporary data storage unit and the local disk device is managed in block units. In comparison with the above, a local disk device having a limited storage capacity can be used effectively. By storing appropriate data in the local disk device, access to the remote disk device via the network is reduced, and access to the local disk device is mainly performed, thereby improving the data write / read processing speed. Further, since the remote disk device and the local disk device are accessed in block units, the data transfer capacity is reduced as compared with the conventional file unit access. Therefore, the load on the network can be reduced, and even when the load on the network is high, stable and high-speed access to the remote disk device can be achieved.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram of a remote disk device access system according to the present invention. The remote disk device access system 1 is configured by connecting a terminal-side computer 10 and a network computer 30 that is a server or a host via a network 40. A magnetic disk device 20 for temporary data storage is connected to the terminal-side computer 10 as a local disk device. Network computer 30
Is connected to a remote magnetic disk device 31 as a remote disk device. The local disk device and the remote disk device may be configured using an optical disk other than a magnetic disk, an optical disk device, or the like.

Magnetic disk device 20 for temporary data storage
Is a block management table 21 and a data storage unit 22
, A free list start block number storage unit 23, and a free list end block number storage unit 24. The data storage unit 22 is divided into blocks of a fixed length, and the state is managed by the block management table 21.

FIG. 2 is an explanatory diagram showing the configuration and operation of the block management table and each number storage unit. The block management table 21 includes, as shown in FIG.
Assuming that the information of each block of No. 2 is one entry, each entry has four items of a block number, a corresponding remote block, a next block, and a write.

The block number is a number (X1, X2,...) For identifying each block of the data storage unit 22 shown in FIG.
…). In the corresponding remote block, data of numbers (Y1, Y2,...) Assigned to divide the remote magnetic disk device 31 into blocks of the same size as the data storage unit 22 and identify the blocks are stored. . Since each block of the data storage unit 22 is finite, a block to be invalidated at the time of importing new data is determined, and new data is read there. However, a block (free list) in which blocks are arranged in the order of invalidation is created. Keep it.

Actually, in the free list, the number of the block to be invalidated first is registered in the free list start block number storage unit 23, and the number of the block to be invalidated next is set to the number of the block registered in 23. Register to the next block item. This is repeated, and the number of the last invalidated block is registered in the free list end block number storage unit 24.

In the write item, whether the block is taken in for writing or that taken in for reading is written by symbols of ○ and ×, respectively.

The data on the remote magnetic disk device 31 is divided into blocks of the same size as the data storage unit 22 and read into the data storage unit 22 in block units.
The terminal-side computer 10 includes an application program 11, a data read processing unit 12, and a data write processing unit 13.

The data read processing unit 12 receives data from the remote magnetic disk device 3 from the application program 11.
When a read request is supplied to the data on the data storage unit 1, the block management table 21 is searched to determine whether or not the requested data area is in the data storage unit 22. The data is read and passed to the application program 11. If there is no requested data area, the data read processing unit 12 reads data from the remote magnetic disk device 31 side,
After that, the data is passed to the application program 11.

When a write request is supplied from the application program 11, the data write processing unit 13 searches the block management table 21 to determine whether or not the requested data area is on the data storage unit 22. The storage unit 22 is overwritten. If there is no requested data area, the data write processing unit 13 secures a new block in the data storage unit 22 and writes the data.

Next, the operation of the remote disk device access system 1 will be described with reference to FIGS. First,
The reading process will be described. The application program 11 issues a request to read data in the remote magnetic disk device 31 to the data read processing unit 12. The data read processing unit 12 searches the block management table 21 to determine whether a data area including data requested by the application program 11 is present in the data storage unit 22. If there is a data area, the data read processing unit 12 Then, the data is read from the data storage unit 22, the data is passed to the application program 11, and the reading process ends.

When the data read processing unit 12 searches the block management table 21 and finds that there is no required data area in the data storage unit 22, the data read processing unit 12 reads data from the remote magnetic disk device 31 via the network 40 and the network computer 30. The data is read out in units of blocks, the data read out in units of blocks is stored in the data storage unit 22, and the data read out from the remote magnetic disk device 31 is passed to the application program 11 to complete the reading process.

When data is stored in the data storage unit 22, the block existing on the data storage unit 22 is invalidated and overwritten. The overwritten block is registered in the free list start block number storage unit 23. Use the block that has been set. In the block management table 21, information indicating which block on the remote magnetic disk device 31 corresponds to the selected block on the data storage unit 22 is written.

Next, the writing process will be described. The application program 11 issues a data write request to the remote magnetic disk device 31 to the data write processing unit 13. The data write processing unit 13 searches the block management table 21 to determine whether a data area requested by the application program 11 is present in the data storage unit 22, and if there is a data area, overwrites the data in the data storage unit 22. If there is no data area, a new block is secured on the data storage unit 22 and data is written there. In this case, the information previously stored in the block is written back to the corresponding block on the remote magnetic disk device 31, and then new data is written.

In the case of the write process, similarly to the case of the read process, the free list start block number storage section 23
Becomes a block that is invalidated due to new data, and the table is updated at the same time as the block is fetched. In the case of writing, since the data content in the data storage unit 22 differs from the data content in the remote magnetic disk device 31, when the writing request of the application program 11 is completed, the data content in the data storage unit 22 is completed. The area is written back to the remote magnetic disk device 31. Thereby, the content of the data stored in the temporary data storage magnetic disk device 20 and the content of the data stored in the remote magnetic disk device 31 can be matched.

Next, the same application program 1
A case in which read and write requests are mixed in 1 will be described. It is assumed that after the data write processing, a read request is issued from the application program 11. The data read processing unit 12 searches the block management table 21 to determine whether a data area including the data requested by the application program 11 is present in the data storage unit 22. If there is data, the data read processing unit 12 reads the data from the data storage unit 22; The data read from the storage unit 22 is passed to the application program 11.

If there is no data in the data storage unit 22, the data is fetched from the remote magnetic disk device 31 into the data storage unit 22 in block units, and the data is passed to the application program 11, and the processing is terminated. In this case, similarly to the above description, it is necessary to perform block exchange on the data storage unit 22. If the block to be invalidated based on the block management table 21 has data for writing, After the contents are written back to the corresponding block on the remote magnetic disk device 31, the data of the block corresponding to the data requested by the application program 11 is read out from the corresponding block on the remote magnetic disk device 31 and taken in.

The same application program 1
If there is a write request after the data reading process in 1, the data write processing unit 13 searches the block management table 21 to check whether the requested data area is in the data storage unit 22. If there is data, the write processing unit 13 overwrites the data in the data storage unit 22. When a block is originally taken into the data storage unit 22 for reading, information to that effect is written in the block management table 21. If there is no block containing the requested data in the data storage unit 22, the data write processing unit 13 secures a new block on the data storage unit 22, and writes the data there. Data write processing unit 1
3 reflects the contents of the block on the data storage unit 22 to the remote magnetic disk device 31 when the mixed read / write processing ends.

Referring to FIG. 2, block management table 2
The operation of managing the data in the data storage unit 22 in block units based on No. 1 will be described. When it is necessary to replace blocks on the data storage unit 22 in the reading process,
The block (n) registered in the free list start block number storage unit 23 is to be replaced. Here, first, it is checked whether the item “write” on the table of n is ○ or ×. ○
In the case of (1), this indicates that the block is a block taken in for writing, so that the contents of the block are written into the corresponding block (Ya) of the remote magnetic disk device 31. Thereafter, the data block (Yb)
Is read into block n.

When the data is read, the data read processing unit 12 updates the block management table 21.
First, Yb is put in the “remote block” corresponding to the entry of the block number n. Since the block n is at the end of the free list, the “next block” is
-. The item of “writing” is x. n becomes the latest block on the data storage unit 22 and is registered in the free list end block number storage unit 24. At the same time, the information of the related block is updated. On the free list, m, which is the block next to n, becomes the head of the free list and is registered in the free list start block number storage unit 23. Until now, n is put in the “next block” of l, which is the last part of the free list.

Next, a case where a block exchange on the data storage unit 22 is performed in the writing process will be described. In this case, the method of searching for a replacement block is the same as in the case of the reading process, but the “write” item in the block management table 21 is updated. If the “write” item is “x” (block for read processing), the data write processing unit 13 rewrites it to “○”.

With the above configuration, the remote disk device access system 1 shown in FIG. 1 uses the magnetic disk device of another computer connected via a network to reduce the capacity shortage of the magnetic disk device on the terminal side. When the countermeasure of the above is used, a local magnetic disk device can be used as a temporary data storage unit.
The magnetic disk device used as a temporary data storage unit is
A local magnetic disk drive with limited storage capacity compared to a conventional system that temporarily stores data in file units on a magnetic disk drive directly connected without a network because it is managed in blocks. Can be used effectively.

If the appropriate data is stored in the temporary data storage magnetic disk device 20 directly connected to the terminal side computer 10, the data requested by the application program can be directly transmitted from the temporary data storage magnetic disk device 20. It is possible to read and write data requested by the application program directly to the magnetic disk device 20 for temporary data storage. Therefore, the speed of the reading and writing processes is greatly improved as compared with the conventional configuration for reading or writing data of the remote magnetic disk device via the network. In addition, the remote magnetic disk device connected via the network is less affected by the load on the network, and can be used stably and at high speed.

Next, another embodiment of the present invention will be described. FIG. 3 is a block diagram of another remote disk device access system according to the present invention, and FIG. 4 is an explanatory diagram showing an operation of performing block management of data in a data storage unit based on a block management table.

The remote disk device access system 2 shown in FIG. 3 is configured by connecting a terminal-side computer 50 and a network computer 30 which is a server or a host via a network 40. A magnetic disk device 60 for temporary data storage is connected to the terminal-side computer 50 as a local disk device. A remote magnetic disk device 31 is connected to the network computer 30 as a remote disk device. The local disk device and remote disk device are
An optical disk other than a magnetic disk, an optical disk device, or the like may be used.

The terminal-side computer 50 includes an application program 11, a data read processing unit 12,
A data write processing unit 13 is provided, and a block management table 51, a free list start block number storage unit 53, and a free list end block number storage unit 54 are arranged on the memory 52 of the terminal-side computer 50. In the example shown in FIG. 1, the block management table 2
1, the block number storage sections 23 and 24 are provided on the temporary data storage disk device 20 side, and the terminal side computer 10
Obtains block management data, start / end block number data, etc. by accessing the temporary data storage disk device 20. On the other hand, in the configuration shown in FIG. 3, since the block management table 51 and the respective block number storages 53 and 54 are arranged in the memory 52 of the terminal-side computer 50, the block management data, the start / end block High-speed access to number data, etc. Thus, the speed of the block management process is increased.

Next, the operation of the remote disk device access system 2 shown in FIG. 3 will be described. First, the reading process will be described. Application program 1
When 1 issues a read request to the remote magnetic disk device 31, the data read processing unit 12 searches the block management table 51 and checks whether the data area requested by the application program 11 is in the data storage unit 22. . If the data in the area including the data requested by the application program 11 is stored in the temporary data storage magnetic disk device 60, the data read processing unit 12
2 is read from the requested data area, and all of the read data or a portion of the data requested by the application program 11 is stored in the application program 1.
1 to end the reading process.

If the data read processing unit 12 searches the block management table 51 and finds that there is no area containing the requested data in the data storage unit 22, the data read processing unit 12 reads the data from the remote magnetic disk device 31 in block units, The block data read from the magnetic disk device 31 is stored in the data storage unit 22 of the magnetic disk device 60 for temporary data storage, and the data read from the remote magnetic disk device 31 is passed to the application program 11 to perform a read process. finish.

When data is stored (written) in the data storage unit 22, the block previously stored in the data storage unit 22 is invalidated and overwritten, but the overwritten block is stored in the free list start block number storage unit 53. Use the registered block. Block management table 5
In 1, information indicating which block on the remote magnetic disk 31 the selected block on the data storage unit 22 corresponds to is written.

Next, the writing process will be described. When the application program 11 issues a write request to the remote magnetic disk device 31, the data write processing unit 13 searches the block management table 51 and checks whether the data area requested by the application program 11 is in the data storage unit 22. If there is a data area, the data is overwritten in the data storage unit 22. If there is no data area, a new block is secured on the data storage unit 22 and data is written there. In this case, the data write processing unit 13 writes the new data after writing the information previously stored in the block back to the corresponding block on the remote magnetic disk device 31.

In the case of the writing process, similarly to the case of the reading process, the free list start block number storage 53
Becomes a block that is invalidated due to new data, and the table is updated at the same time as the block is fetched. In the case of writing, the contents of the data in the data storage unit 22 are stored in the remote magnetic disk device 3.
1 is temporarily different from the contents of the data stored in the first data. Therefore, the data write processing unit 13 writes the data in the data storage unit 22 back to the remote magnetic disk device 31 when one write request from the application program 11 is completed. As a result, the contents of the data stored in the temporary data storage magnetic disk device 60 and the contents of the data stored in the remote magnetic disk device 31 can be matched.

Next, the same application program 1
A case in which read and write requests are mixed in 1 will be described. It is assumed that a read request is received from the application program 11 after the data write processing. The data read processing unit 12 searches the block management table 51 to check whether the data area requested by the application program 11 exists in the data storage unit 22.
If there is a data area, the data is read from the data storage unit 22 and passed to the application program 11. If there is no data area in the data storage unit 22, the data is fetched from the remote magnetic disk device 31 into the data storage unit 22 in block units, the data is passed to the application program 11, and the processing is terminated.

In this case, as in the above description, it is necessary to exchange blocks on the data storage unit 22. If the block to be invalidated has data for writing, the block management table 51 is referred to. Writes the content back to the corresponding block on the remote magnetic disk 31, and then reads the block corresponding to the request from the application program 11 from the remote magnetic disk 31. In addition, the same application program 11
When there is a write request after the data read processing, the data write processing unit 13 searches the block management table 51 and finds that the requested data area is in the data storage unit 22.
Find out if there is.

If there is data, the write processing unit 13
The data is overwritten in the data storage unit 22. When a block is originally loaded into the data storage unit 22 for reading, information to that effect is written in the block management table 51. If there is no block including the requested data area in the data storage unit 22, the data write processing unit 13
Secures a new block on the data storage unit 22, and writes data to the newly secured block. The data write processing unit 13 reflects the contents of the block on the data storage unit 22 to the remote magnetic disk device 31 when the mixed read / write processing ends.

Next, an operation of managing data in the data storage unit 22 on a block basis based on the block management table 51 will be described with reference to FIG. In the reading process,
When the exchange of the blocks on the data storage unit 22 becomes necessary, the block (n) registered in the free list start block number storage unit 53 becomes an exchange target. Here, first, it is checked whether the item “write” on the table of n is ○ or ×. In the case of ○, it indicates that the block is a block fetched for writing, so the contents of the block are written to the corresponding block (Ya) of the remote magnetic disk device 31. Thereafter, the data block (Y
b) is read into the block number n. When the data is read, the data read processing unit 12 updates the block management table 51.

First, Yb is entered in the “corresponding remote block” of the entry of “block number” n. Since the block number n is at the end of the free list, the "next block" is "---". The item of “writing” is x. n is the latest block on the data storage unit 22, and the free list end block number storage unit 5
4 is registered. At the same time, the information of the related block is updated. On the free list, the next block of n, m
Becomes the head of the free list and is registered in the free list end block number storage unit 54. Until now, the “next block” of l, which was the end of the free list,
n is entered.

Next, a case where a block exchange on the data storage unit 22 is performed in the writing process will be described. In this case as well, the method (operation procedure) of searching for a replacement block is the same as in the case of the reading process, but the “write” item of the block management table 41 is updated. Data write processing unit 13
Is rewritten to ○ if the “write” item is × (block for read processing).

[0051]

As described above, the remote disk device access system according to the present invention uses the local disk device as a temporary data storage unit and manages the local disk device in block units. Compared to the method of copying in file units of
The local disk device having a limited storage capacity can be used effectively. By storing appropriate data in the local disk device, access to the remote disk device via the network is reduced, and access to the local disk device is mainly performed, thereby improving the data write / read processing speed.

Further, since the remote disk device and the local disk device are accessed in block units, the data transfer capacity is reduced as compared with the conventional file unit access. For this reason, the load on the network can be reduced, and stable and high-speed access to the remote disk device can be achieved even when the load on the network is high. Further, by arranging the block management table on the memory of the terminal-side computer, the block management can be performed at high speed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a remote disk device access system according to the present invention;

FIG. 2 is an explanatory diagram showing an operation of performing block management of data in a data storage unit based on a block management table in the configuration of FIG. 1;

FIG. 3 is a block diagram of another remote disk device access system according to the present invention;

FIG. 4 is an explanatory diagram showing an operation of performing block management of data in a data storage unit based on a block management table in the configuration of FIG. 3;

[Explanation of symbols]

 1, Remote disk device access system 10, 50 Terminal side computer 11 Application program 12 Data read processing unit 13 Data write processing unit 20, 60 Temporary data storage magnetic disk device 21, 51 Block management table 22 Data storage unit 23, 53 Free list start block number storage unit 24, 54 Free list end block number storage unit 30 Network computer 31 Remote magnetic disk 40 Network

Continuation of the front page (56) References JP-A-3-87939 (JP, A) JP-A-4-181444 (JP, A) JP-A-5-100926 (JP, A) JP-A-6-12388 (JP) JP-A-6-35769 (JP, A) JP-A-6-290090 (JP, A) JP-A-8-69401 (JP, A) JP-A-9-81429 (JP, A) 9-204358 (JP, A) JP-A-9-244931 (JP, A) JP-A-9-288677 (JP, A) JP-A-10-31604 (JP, A) (58) Fields investigated (Int. Cl. ^7, DB name) G06F 12/00

Claims (5)

(57) [Claims] 1. A fixed length connection via a network
In a remote disk device access system configured to execute an application program on a terminal-side computer using a remote disk device having a storage area divided into blocks as a storage device, the same size as the remote disk device is used. Minutes into blocks
A local disk device having a divided storage area and used as a temporary storage area for data in the terminal-side computer , wherein the terminal-side computer stores data from the application program for the remote disk device. Read from the remote disk device in response to a read request and a write request of
Data to be written or data to be written
Block in the remote disk device of the
Corresponding to the block in the local disk device.
At the time of the storage, the remote
Data for writing to the disk drive has already been stored.
If there is, the write data is
A remote disk device access system for writing to a block in the remote disk device. 2. The terminal-side computer includes a data read processing unit, the local disk device has a block management table , and is first invalidated.
Start list that stores information indicating the
A lock information storage unit, the data reading processing unit, to the read request of data stored in the remote disk device from said application program, searches the block management table, the request data is stored the In the remote disk device
The block corresponding to the block is the local disk
If the request data exists in the device, the request data is read from the block and passed to the application program.
And in the remote disk device where the request data is stored.
Block is the local disk corresponding to the block
If not in the apparatus, Shi read out the requested data from the remote disk apparatus via the network
To the application program, and
Request data is stored in the free list start block information
The local data specified by the information stored in the
The request data is stored in a block in the disk device.
Stored in association with the remote disk unit block
2. The remote disk device access system according to claim 1, wherein: 3. The terminal-side computer has a data write processing unit, the local disk device has a block management table , and is first invalidated.
Start list that stores information indicating the
A lock information storage unit , wherein the data write processing unit searches the block management table in response to a data write request from the application program to the remote disk device, and writes the requested data to the remote disk device.
The block corresponding to the block in the location is the local data.
If the data exists in the disk device, the data of the block is overwritten and the requested data is written to the remote disk device.
The block corresponding to the block in the location is the local data.
If the request data does not exist in the disk device, the
Information stored in the free list start block information storage unit.
In the local disk device specified by the
2. The remote disk device access system according to claim 1, wherein the information is stored in a lock . 4. The terminal-side computer includes a data read processing unit, a block management table in a memory of the terminal-side computer , and
Free library containing information indicating the block to be invalidated
Place the strike start block information storage unit, the data reading processing unit, to the read request of data stored in the remote disk device from said application program, searches the block management table, stores the requested data In the remote disk device
The block corresponding to the block is the local disk
If the request data exists in the device, the request data is read from the block and passed to the application program.
And in the remote disk device where the request data is stored.
The block corresponding to the block is the local disk
If not in the apparatus, Shi read out the requested data from the remote disk apparatus via the network
To the application program, and
Request data is stored in the free list start block information
The local data specified by the information stored in the
The request data is stored in a block in the disk device.
Stored in association with the remote disk unit block
2. The remote disk device access system according to claim 1, wherein: 5. The terminal-side computer includes a data write processing unit, a block management table on a memory of the terminal-side computer , and
Free library containing information indicating the block to be invalidated
And a data write processing unit for searching for the block management table in response to a data write request from the application program to the remote disk device, and writing the requested data to the remote control unit. Disk mount
The block corresponding to the block in the location is the local data.
If the data exists in the disk device, the data of the block is overwritten and the requested data is written to the remote disk device.
The block corresponding to the block in the location is the local data.
If the request data does not exist in the disk device, the
Information stored in the free list start block information storage unit.
In the local disk device specified by the
2. The remote disk device access system according to claim 1, wherein the information is stored in a lock .