KR100952599B1 - User computer using local disk as caching device, method for using the same and hybrid network storage system - Google Patents

Abstract

All or part of the local disk is allocated as a cache for the virtual disk to use the network storage, and the local disk and the network storage are used together, and the block-based protocol is used to access files over the network. It can improve the overall speed of the running virtual disk and use the same performance as the local disk. In addition, by sorting and storing data in the cache, predetermined data is not stored in the cache so that confidentiality can be maintained, and other predetermined data can not be erased from the cache so that the file can be used even in the event of a network failure.

Web Hard, Local Disk Cache, Network Storage

Description

USER COMPUTER USING LOCAL DISK AS CACHING DEVICE, METHOD FOR USING THE SAME AND HYBRID NETWORK STORAGE SYSTEM}

The present invention relates to a user computer using a local disk as a cache, a method of using the same, and a hybrid network storage system. More specifically, a virtual disk is provided in the user computer, so that the network storage connected to the user computer and the internet through the internet is the same as the local disk of the user computer. The present invention relates to a user computer using the network storage more efficiently by using the same function and using the local disk of the user computer as a cache for the virtual disk, a method of using the same, and a hybrid network storage system.

In general, a hard disk installed in a user computer such as a desktop or a notebook is a local disk, which is physically fixed to the user computer. The local disk has advantages of large data storage capacity, accessibility, and speed.

However, although the local disk has the advantages described above, mobility and data sharing on a network are difficult, and a local disk must be purchased separately for capacity expansion.

Therefore, as one method for improving such a problem, when moving the data stored in the local disk to another computer to store or use in another computer is mainly used a removable disk such as a USB memory or an external hard disk.

 However, while the removable disk also has the advantages of fast speed and good portability, there are still disadvantages that the capacity is smaller than that of the local disk, it is difficult to share data with various people, and there is a risk of loss.

Therefore, when data is shared with many people, it is difficult to share data with only local disk and removable disk. Therefore, as a different method, recently, a plurality of user computers store and share data over the Internet like Web hard. Network storage is often used.

Hereinafter, a conventional network storage system will be described in more detail.

1 is a schematic diagram illustrating a network storage system using a conventional virtual disk.

As shown in FIG. 1, the storage device 110 of the user computer 100 is divided into a local disk 120 and a virtual disk 130. The virtual disk 130 is connected to the storage server 150 through the Internet. When a user requests a file or changes a file through the virtual disk 130, the contents are transferred to the storage server 150 through the Internet. The files 161, 162, 163, and 164 stored in the network storage 160 are requested or changed. Such conventional network storage uses file-based protocols such as nfs and samba for file sharing. The file-based protocol reads and stores data stored in the network storage 160 in units of files. This means that the user computer 100 and the storage server 150 manage files using their own file systems.

Therefore, if the file-based protocol is used, the storage server 150 also needs to manage files stored in the network storage 160 using its own file system, thus using a large amount of server resources to manage large files or a large number of files. When it is necessary to load a lot of load on the storage server 150, the use speed of the virtual disk 130 running in the user computer 100 is significantly slowed and unstable.

As such, recently, the widespread use of the high-speed Internet has enabled the use of network storage. The network storage is easy to share data and does not need to carry storage devices, so it is not only portable but also easy to expand capacity. On the other hand, the speed of accessing the network storage depends on the speed of the network, and in the event of a network failure, the files stored in the network storage cannot be used at all. There are many problems to follow.

Due to the shortcomings of each of these storage devices, until now, only one storage device is used in using the storage device, and different storage devices are used for each purpose. That is, while most of the data is stored on the local disk, which is the main storage device, important data that is not used for a long time or needs to be stored separately among the data stored on the local disk are sorted and stored in the backup device, and the data is used on another computer. Copy it to removable disks or network storage if you need to share data with others.

On the other hand, in the case of Webhard, users access and use network storage through the web, and only file upload and download functions are provided through the web, so the file access method is different from general storage devices and does not work with other applications. There is such an inconvenience. In recent years, network storage can be recognized as a local disk in a computer through a dedicated program, so it can be used like a regular disk.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and the disadvantages of the two storage devices are compensated for by using a local disk and a network storage together by allocating a part or all of the local disk as a cache for a virtual disk for using the network storage. It aims to provide a hybrid network storage system that utilizes several advantages.

In addition, an object of the present invention is to improve the overall speed of a virtual disk running on a user's computer using a block-based protocol as a method for file access over a network.

In addition, an object of the present invention is to make it possible to maintain confidentiality by selecting and storing data in a cache allocated to a local disk and to use predetermined data even in the event of a network failure.

In order to achieve the above object, according to an aspect of the present invention, in a user computer connected to a storage server via the Internet, a virtual disk for making network storage installed in the storage server to function as a storage device present in the user computer And a local disk having a first storage unit used as a cache for the virtual disk. The local disk may further include a second storage unit used inside the user computer without being used as a cache for the virtual disk.

It is preferable that data is transmitted and received between the virtual disk and the network storage using a block-based protocol, so that the user computer directly controls the data blocks stored in the network storage.

The virtual disk may further include cache managing means for searching whether the predetermined data exists in the first storage unit when the predetermined data is requested from a user, and the cache managing means may include the requested data. If present in the first storage unit, provides the user with the predetermined data requested from the first storage unit, and if the requested predetermined data does not exist in the first storage unit from the storage server. Preferably, the requested data is received and provided to the user.

The virtual disk further includes cache management means for searching whether the predetermined data exists in the first storage unit when a change of predetermined data is requested from a user, and the cache managing means further includes the requested management information. Data of the first storage unit is stored, the predetermined data stored at the first storage unit is changed, and the changed predetermined data is stored in the network storage, and the requested data is stored in the first storage unit. 1, if the storage unit does not exist, the requested data present in the network storage may be changed and the changed data may be provided.

The cache management means may further include a swap-in determining means for determining whether the predetermined data provided from the storage server can be swapped in the first storage unit, and the swap-in determining means includes: When it is determined that predetermined data may be swapped in, the cache managing means may further include means for determining whether there is free space in which the predetermined data is to be stored. In addition, when there is free space in the first storage unit, the predetermined data is stored in the free space, and the cache managing means, when there is no free space in which the predetermined data is stored in the first storage unit, And a swapout means for selecting and deleting data to be swapped out of the data stored in the first storage unit, and storing the predetermined data in the deleted data space, wherein when selecting the data to be swapped out. It is desirable to have a swapout prevention option to ensure that certain data is not deleted.

In addition, a method of using a user computer comprising a virtual disk for making network storage installed in a storage server connected through the Internet as a storage device existing in a user computer, and a local disk having a cache for the virtual disk. A data retrieval step of searching for whether the predetermined data exists in the cache in the virtual disk when a request for predetermined data is received from the virtual disk and providing the predetermined data to a user when the predetermined data exists, and the predetermined data exists. If not, a method of using a user computer is provided, including a data receiving step of receiving the predetermined data from the storage server.

In addition, a method of using a user computer comprising a virtual disk for making network storage installed in a storage server connected through the Internet as a storage device existing in a user computer, and a local disk having a cache for the virtual disk. A data retrieval step of retrieving whether or not the predetermined data exists in the cache in the virtual disk when a change request for predetermined data is received from the virtual disk; When the predetermined data is stored in the network storage, and the predetermined data does not exist, the predetermined data that is changed and the modified data existing in the network storage are simultaneously received from the storage server. A method of using a user computer is provided, including a data receiving step.

The data receiving step may further include a swap-in determining step of determining whether the predetermined data provided from the storage server can be swapped in the cache, wherein the predetermined data is determined in the swap-in determining step. If it is determined that the data can be swapped in, the cache managing means may further include determining whether there is free space in which the predetermined data is to be stored in the cache.

If it is determined that there is free space to be stored in the cache, the method may further include storing the predetermined data in the free space. When it is determined that there is no free space to be stored in the cache, data stored in the cache Selecting and deleting data to be swapped out of the data; and storing the predetermined data in the deleted data space, wherein the specific data is not deleted when the data to be swapped out is selected. It is desirable to have prevention options.

In the data transmission and reception between the virtual disk and the network storage, a block-based protocol is used, whereby the user computer directly controls the data blocks stored in the network storage.

According to one aspect of the present invention, there is also provided a computer readable recording medium having recorded thereon a program for executing the method on a computer.

According to another aspect of the present invention, there is provided a local disk having a virtual disk for making network storage installed in a storage server connected through the Internet function as a storage device existing in a user computer, and a first storage unit used as a cache for the virtual disk. A hybrid network storage system is provided that includes a user computer comprising a disk and the storage server.

According to the present invention, by using a virtual disk by allocating a part or all of the local disk as a cache for the virtual disk, it is possible to use the virtual disk more quickly and stably than the conventional network storage system.

In addition, according to the present invention, by using a block-based protocol for file sharing over a network, the overall speed of the virtual disk running on the user computer can be improved, and the virtual disk can be used with the same performance as the local disk.

In addition, according to the present invention, by selecting and storing data in the cache allocated to the local disk, predetermined files are not stored in the cache so that confidentiality is possible, and other predetermined files are not erased from the cache so that the network fails. The file is also available.

Hereinafter, with reference to the accompanying drawings will be described a specific embodiment of the present invention, but this is only an example and the present invention is not limited thereto.

A local disk is a device that is actually installed on your computer and can store data.

Network storage refers to a storage device connected to a network. The storage device of a local device or a user's computer alone is used when there is insufficient storage space or when data sharing is required at various places in remote areas.

The cache refers to a high speed memory device used for storing data frequently used in a high speed memory device, thereby speeding up data input / output without having to load it from a low speed device. In the present invention, using a local disk as a cache means that the local disk is used as a cache by storing a part of data stored in the network storage on the local disk having a faster data input / output speed than the network storage.

2 is a schematic diagram illustrating a hybrid network storage system using a local disk as a cache according to an embodiment of the present invention.

Referring to FIG. 2, the storage device 210 of the user computer 200 includes a local disk 220 and a virtual disk 230, and the user computer 200 stores a shared data through the Internet. It is connected to a storage server 250 having a storage 260.

The local disk 220 is divided into a first storage unit 222 allocated as a cache partition and a second storage unit 221 allocated as a general partition, and the first storage unit 222 is a virtual disk 230. While the storage space used as a cache of the second storage unit 221 is a storage space that functions as a normal storage device in the user computer 200.

The first storage unit 222 is composed of several cache blocks 231, 232, 233, and 234, and each cache block 231, 232, 233, and 234 is a block of the network storage 260. 262, 263, 264, 265, and 266, the user reads the cache through the virtual disk 230 and stores it.

In detail, when a user requests a predetermined file from the virtual disk 230, the virtual disk 230 first includes a requested file in the cache blocks 231, 232, 233, and 234 in the first storage unit 222. If there is one, then the file is provided from the corresponding cache block (231, 232, 233, 234). If the file does not exist in the cache blocks 231, 232, 233, and 234, the blocks 261, 262, 263, 264, in the network storage 260 in which the requested file is stored from the storage server 250 are stored. 265 and 266, the corresponding block is received and stored in the first storage unit 222, and the corresponding file is provided to the user.

In the same way, when the user requests the virtual disk 230 to change the contents of a predetermined file, the virtual disk 230 first requests the cache blocks 231, 232, 233, and 234 in the first storage unit 222. First, check whether the file exists, and if it exists, the changed file is stored in the corresponding cache block (231, 232, 233, 234), and at the same time, the changed block is stored in the network storage 260 through the Internet. , 233, 234 and blocks 261, 262, 263, 264, 265, and 266 of the network storage 260 are synchronized.

If the file does not exist in the cache blocks 231, 232, 233, and 234, the block 261, 262, 263, 264 in the network storage 260 in which the file requested to be changed from the storage server 250 is stored is stored. , 265 and 266, the corresponding block is received, the corresponding file is changed and stored in the first storage unit 222 and simultaneously stored in the corresponding block of the network storage 260. Alternatively, among the blocks 261, 262, 263, 264, 265, and 266 in the network storage 260, the corresponding block is immediately changed and the changed block is received and stored in the first storage unit 222.

As such, when the virtual disk 230 requests a file stored in the storage server 250 or requests to change the file, the virtual disk 230 first searches the cache blocks 231, 232, 233, and 234 to check whether the file exists. Therefore, if the file exists in the cache blocks 231, 232, 233, and 234 at that time, the file can be used quickly and stably.

In general, as can be seen in the performance improvement when using cache memory or disk cache, it is very likely to be reused in the near future once it has been used. The number of comings can be reduced, which can improve performance. In addition, the local disk is large enough to store most of the files for daily work, so if you use a large portion of the local disk as a cache, most of the frequently used files are stored on the local disk. Since there is little traffic, the user can hardly notice the difference in speed from using the local disk and can use the virtual disk without any inconvenience in case of network failure.

Of course, by providing a caching function in a commonly used web browser, files of previously visited web pages are stored in a cache space, so when the user revisits the web pages later, the files do not need to be retrieved again. This may be improved, but since the cache function only works for files included in the web page, it is difficult to obtain the cache effect even when using the web hard disk.

FIG. 3 is a functional block diagram illustrating a user computer and a storage server configuring a hybrid network storage system using a local disk as a cache according to an embodiment of the present invention.

Referring to FIG. 3, the user computer 300 includes an application 310 which is a program used by the user, a virtual disk 320 connected to the network storage 260 via the Internet, a local disk 220, and the local disk. Cache management means 330 for managing the cache, the block-based protocol means 340 for transmitting data on a block basis over the Internet.

The storage server 250 also includes a network storage 260 and block-based protocol means 350, which are divided into blocks 261, 262, 263, 264, 265, and 266. have.

Looking at the function of each functional block in detail, the application 310 refers to a program actually used by the user, and performs a task desired by the user. The application 310 may directly access the file or may access the file via an operating system (OS). In FIG. 3, the application 310 simply expresses a request change of a file.

The virtual disk 320 is not a disk physically installed inside the user computer 300 but is connected to the network storage so that the network storage functions as if it is actually installed on the user computer. Manage.

The cache managing means 330 is a means for managing the cache blocks 231, 232, 233, and 234 existing in the first storage unit 222 of the local disk 220. The files desired by the virtual disk 320 are cached. It determines whether the block 231, 232, 233, 234 exists, and manages the operation of reading, storing, or deleting the cache block 231, 232, 233, 234. As mentioned above, the cache for the virtual disk divides the first storage unit 222 into a separate partition on the local disk 220. Therefore, the first storage unit 222 is not affected even when an error occurs in the second storage unit 221 because it is operated separately from the second storage unit 221.

The block-based protocol means 340 means a means for performing data transfer in units of blocks between storages connected to the Internet. An example thereof is an Internet Small Computer Systems Interface (iSCSI). iSCSI organizes small computer systems interface (SCSI) commands and data into and out of a TCP / IP network. Shared disks using iSCSI allow multiple nodes to access concurrently over a TCP / IP network.

When using a file-based protocol, which is a method used in a conventional network storage system, when a file stored in the network storage 260 is used in a virtual disk, the file stored in the network storage 260 passes through the file system of the storage server 250. Approached. On the other hand, when using a block-based protocol, it is possible to directly control the data blocks of the storage server 250 from the user computer (300). In other words, controlling a block of storage directly is a subordinate task than controlling a file on a storage device, which means controlling the storage device more broadly than simply controlling a file.

Therefore, when data is transferred on a block-based basis, unlike the file-based scheme, it is possible to make the network storage 260 behave like the same disk as the local disk 220 in the user computer 300, thereby stably using the virtual disk. In this case, the execution speed of the virtual disk is improved by not using the file system of the storage server 250.

Specifically, referring to FIG. 3, the coupling relationship between the respective functional blocks is operated. The user operates the application 310, which is a computer program, to perform a desired task through the user computer 300. The application 310 requests or changes a predetermined file for the virtual disk 320 to perform a corresponding operation. When the file exists on the virtual disk 320, the application 310 sends the file to the virtual disk 320. Request or order a change.

Then, the virtual disk 320 first checks whether the corresponding file exists in the first storage unit 222 through the cache management means 330. The cache managing means 330 reads the file when the file exists in the cache blocks 231, 232, 233, and 234 of the first storage unit 222, and transmits the file to the virtual disk 320. Change the file and store it in the cache blocks 231, 232, 233, 234, and at the same time block 261, 262, 263, 264, 265, 266 of the network storage 260 via the block based protocol means 340 and 350. ) To synchronize the changes.

However, if the file does not exist in the cache blocks 231, 232, 233, and 234, the cache management means 330 uses the block based protocol means 340 and 350 to block the block 261,. Among the 262, 263, 264, 265, and 266, the block in which the file exists is transmitted as it is and stored in the cache block (231, 232, 233, 234), or when the file needs to be changed, the received block is changed and cached. At block 231, 232, 233, and 234, the changed block is again stored in the network storage 260 and the corresponding file is transferred to the virtual disk 320.

In addition, the cache management means 330 further includes swap-in preventing means for preventing the predetermined data from being stored in the cache, and swap-out preventing means for preventing the predetermined data from being deleted in the cache. (However, not shown in the drawing.)

In this case, swapping out a predetermined data stored in the cache is called swapping out and deleting predetermined data from the cache is called swap out. In general, the cache stores the frequently used data stored in the low speed storage device in the high speed cache to increase its utilization. The size of the storage space of the high speed storage device is the size of the low speed storage device. It is common to be smaller than the storage space. Therefore, as the cache is used, the storage space of the cache becomes insufficient, some of the data stored in the cache must be deleted, and new data is stored in the deleted space. The process of deleting certain data from the cache is called swap out, and the process of storing new data in the cache is called swap-in.

According to one embodiment of the present invention, a swap-in prevention means is added to the cache management means 330 to prevent the predetermined data requiring the security maintenance for the confidentiality of the predetermined data from being stored in the user computer 300. . In addition, by adding a swapout prevention means so that data that always needs to exist in the user computer 300 is not swapped out, predetermined data can be continuously and stably used even when there is a network failure.

4 is a schematic diagram showing an example of using a hybrid network storage system using a local disk as a cache in various computers according to an embodiment of the present invention.

Referring to FIG. 4, a user creates first storages 420, 440, and 460 on local disks 412, 432, and 452 of desktop 410, portable computer 430, and PDA 450, and virtualizes them respectively. Used as a cache space for the disks 411, 431 and 451. Then, by taking the necessary blocks 481, 482, 483, 484, 485, 486 from the same network storage 480, respectively, storing them in the first storage unit 420, 440, and 460, and synchronizing the changed blocks. All computers will be able to use the same system environment.

In some cases, when the local disk 452 is insufficient, such as the PDA 450, the entire local disk 452 may be allocated to the first storage unit 460 which is a cache space for the virtual disk 451. .

In addition, the entire file is basically stored in the network storage 480, so that all the computers 410, 430, and 450 can be used in the same environment, and the data can be shared with multiple people.

In addition, using the local disk as a cache will automatically achieve the same effect as always having the same file system stored on all computers' local disks, without having to copy files. No recovery is necessary.

5 is a flowchart illustrating a process of reading a file from a hybrid network storage using a local disk as a cache according to an embodiment of the present invention.

Referring to FIG. 5, if there is a user's file access request for the virtual disk (S510), first, it is checked whether the file exists in the cache block (S520), and if present, the file is provided to the user (S530) and the operation is terminated. . In step S520, before requesting a file to the network storage, first check whether the file exists in the cache block, so that the file existing in the cache block is not received through the network, thereby improving the operation speed of the virtual disk.

If the file does not exist, it requests the file to the network storage (S540), receives the block in which the file is stored among the blocks in the network storage (S550), provides the file to the user (S530), and simultaneously receives a block swapped. Check whether the phosphorus is allowed (S560). In step S560, it is checked whether the cache block is allowed to be stored, that is, whether the block is allowed to be swapped in, so as to provide a function of preventing the leakage of confidential documents. Confidential files are not stored in the cache block of the local disk, preventing confidential information from being stored on the user's computer.

Next, if the block received in step S560 is a block that is not allowed to be swapped in, the process is terminated. If the block is allowed to be swapped in, it is checked whether a free cache block exists in the cache of the local disk (S570). If there is a free cache block, the received block is stored in the free block (S590). If the free cache block does not exist, the block to be swapped out is selected by the cache algorithm (S581), the contents of the selected block are deleted (S582), and the received block is stored (S590) and terminated.

 In particular, in S581, a block to be erased from the cache block, that is, a block to be swapped out is selected, and a block that needs to be deleted using a cache algorithm is appropriately selected and the block is deleted in step S582.

In addition, a file that always needs to be always stored in the cache block of the local disk can be set in advance in the cache algorithm so that the block in which the file is stored is not swapped out. These undeleted files can be read from the cache block via the virtual disk even when the network is unavailable.

For example, among the files stored in the virtual disk, files that affect the operation of the system, such as system files, are classified separately so that they are not swapped out so that the operation of the system is not affected even in the event of a network failure.

Meanwhile, the method may be implemented in software and executed on a computer. The software may be implemented in a form that includes one or more software modules that execute some or all of the above described method steps. Software can also be implemented on a variety of platforms in a variety of programming languages.

In addition, software and software modules may be implemented in various service models. For example, when the storage server communicates with a user computer, the method performed on the server may be an application implemented in the form of an application service provider (ASP) and provided and operated according to a request of the user computer. Alternatively, the application may run on the server itself and only the results may be sent to the user's computer. In addition, the software can be implemented in a user-friendly form such as PHP, JSP (JAVA Script Page), etc. to facilitate the user's use.

The software is recorded on various optical, electrical and magnetic recording media such as CD-ROM, floppy disk, flash memory, hard disk, magnetic tape, and can be read and executed by a computer as necessary.

Although the present invention has been described above with reference to specific embodiments of the present invention, this is only an example and does not limit the scope of the present invention. Those skilled in the art can change or modify the described embodiments without departing from the scope of the present invention. Each of the functional blocks described in the present specification may be implemented by various well-known elements such as an electronic circuit, an integrated circuit, and an application specific integrated circuit (ASIC), and may be separately implemented or two or more may be integrated into one. Components such as means described as separate in the specification and claims may be simply functionally distinct and may be physically implemented as one means, and components such as means described as a single element may be It can be made in combination. In addition, each method step described herein may be changed in order without departing from the scope of the present invention, and other steps may be added. In addition, the embodiments described herein may be implemented independently as well as independently combined. It is therefore evident that the scope of the invention should be defined by the appended claims and their equivalents, rather than by the described embodiments.

1 is a schematic diagram illustrating a network storage system using a conventional virtual disk.

2 is a schematic diagram illustrating a hybrid network storage system using a local disk as a cache according to an embodiment of the present invention.

FIG. 3 is a functional block diagram illustrating a user computer and a storage server configuring a hybrid network storage system using a local disk as a cache according to an embodiment of the present invention. FIG.

4 is a schematic diagram showing an example of using a hybrid network storage system using a local disk as a cache in various computers according to an embodiment of the present invention.

5 is a flowchart illustrating a process of reading a file from a hybrid network storage using a local disk as a cache according to an embodiment of the present invention.

Claims (35)

delete delete delete For a user's computer connected to a storage server over the Internet, A virtual disk for making network storage installed in the storage server function as a storage device present in the user computer; And It includes a local disk having a first storage unit used as a cache for the virtual disk, The virtual disk includes cache management means for searching whether the predetermined data exists in the first storage unit when the predetermined data is requested from a user. The cache management means provides the user with the predetermined data requested from the first storage unit, if the requested data exists in the first storage unit. And when the requested data is not present in the first storage unit, receives the requested data from the storage server and provides the requested data to the user. For a user's computer connected to a storage server over the Internet, A virtual disk for making network storage installed in the storage server function as a storage device present in the user computer; And It includes a local disk having a first storage unit used as a cache for the virtual disk, The virtual disk includes cache management means for searching whether the predetermined data exists in the first storage unit when receiving a change request of predetermined data from a user. The cache managing means stores the changed predetermined data in the network storage while changing the predetermined data stored in the first storage unit when the requested predetermined data exists in the first storage unit, And if the requested predetermined data does not exist in the first storage unit, change the requested predetermined data present in the network storage and receive the changed predetermined data. The method according to claim 4 or 5, The cache management means further comprises swap in determining means for determining whether the predetermined data provided from the storage server can be swapped in to the first storage. The method of claim 6, If the swap-in determining means determines that the predetermined data can be swapped in, the cache managing means further includes means for determining whether there is free space for the predetermined data to be stored in the first storage unit. Your computer. The method of claim 7, wherein And if the first storage unit has free space, stores the predetermined data in the free space. The method of claim 7, wherein The cache managing means selects and deletes data to be swapped out of data stored in the first storage unit when there is no free space for the predetermined data to be stored in the first storage unit, and deletes the deleted data space. Swapping means for storing the predetermined data in the; And a swapout prevention option to prevent specific data from being deleted when selecting the data to be swapped out. A method of using a user computer comprising a virtual disk for making network storage installed in a storage server connected through the Internet as a storage device existing in a user computer, and a local disk having a cache for the virtual disk. A data retrieval step of retrieving whether the predetermined data exists in the cache in the virtual disk when a request for predetermined data is received from a user; And And providing the predetermined data to the user when the predetermined data exists, and receiving the predetermined data from the storage server when the predetermined data does not exist. A method of using a user computer comprising a virtual disk for making network storage installed in a storage server connected through the Internet as a storage device existing in a user computer, and a local disk having a cache for the virtual disk. A data retrieval step of retrieving whether the predetermined data exists in the cache in the virtual disk when a change request for predetermined data is received from a user; And When the predetermined data exists, the predetermined data is changed at the same time, and the changed predetermined data is stored in the network storage, and when the predetermined data does not exist, the predetermined data existing in the network storage. And a data receiving step of receiving the changed predetermined data from the storage server at the same time as changing the data. The method of claim 10 or 11, And a swap-in determining step of determining whether the predetermined data provided from the storage server in the data receiving step can be swapped into the cache. The method of claim 12, If it is determined in the swap-in determination step that the predetermined data can be swapped in, the cache management means further comprises determining whether there is free space for the predetermined data to be stored in the cache. Way. The method of claim 13, And if it is determined that there is free space to be stored in the cache, storing the predetermined data in the free space. The method of claim 13, If it is determined that there is no free space to be stored in the cache, selecting and deleting data to be swapped out of the data stored in the cache, and storing the predetermined data in the deleted data space, And a swapout prevention option to prevent specific data from being deleted when selecting the data to be swapped out. The method of claim 10 or 11, Data transmission and reception between the virtual disk and the network storage uses a block-based protocol to directly control data blocks stored in the network storage at the user computer. A computer-readable recording medium having recorded thereon a program for executing the method of claim 10 or 11 on a computer. A computer-readable recording medium having recorded thereon a program for causing the method of claim 12 to be executed on a computer. A computer-readable recording medium having recorded thereon a program for causing the method of claim 13 to be executed on a computer. A computer-readable recording medium having recorded thereon a program for causing the method of claim 14 to be executed on a computer. A computer-readable recording medium having recorded thereon a program for causing the method of claim 15 to be executed on a computer. A computer-readable recording medium having recorded thereon a program for causing the method of claim 16 to be executed on a computer. delete delete delete A user computer including a virtual disk for making network storage installed in a storage server connected through the Internet as a storage device existing in a user computer, and a local disk having a first storage unit used as a cache for the virtual disk; And Including the storage server, The virtual disk includes cache management means for searching whether the predetermined data exists in the first storage unit when the predetermined data is requested from a user. The cache management means provides the user with the predetermined data requested from the first storage unit, if the requested data exists in the first storage unit. And when the requested data is not present in the first storage unit, receives the requested data from the storage server and provides the requested data to the user. A user computer including a virtual disk for making network storage installed in a storage server connected through the Internet as a storage device existing in a user computer, and a local disk having a first storage unit used as a cache for the virtual disk; And Including the storage server, The virtual disk includes cache management means for searching whether the predetermined data exists in the first storage unit when receiving a change request of predetermined data from a user. The cache managing means stores the changed predetermined data in the network storage while changing the predetermined data stored in the first storage unit when the requested predetermined data exists in the first storage unit, And if the requested predetermined data does not exist in the first storage unit, the requested predetermined data present in the network storage is changed and provided with the changed predetermined data. The method of claim 26 or 27, And the cache management means further comprises swap-in determining means for determining whether the predetermined data provided from the storage server can be swapped in to the first storage unit. 29. The method of claim 28, If the swap-in determining means determines that the predetermined data can be swapped in, the cache managing means further includes means for determining whether there is free space for the predetermined data to be stored in the first storage unit. Hybrid network storage system. 30. The method of claim 29, And storing the predetermined data in the free space when there is free space in the first storage. 30. The method of claim 29, The cache managing means selects and deletes data to be swapped out of data stored in the first storage unit when there is no free space for the predetermined data to be stored in the first storage unit, and deletes the deleted data space. Swapping means for storing the predetermined data in the; And a swapout prevention option to prevent specific data from being deleted when selecting the data to be swapped out. The method according to claim 4 or 5, The local disk further includes a second storage unit used inside the user computer instead of being used as a cache for the virtual disk. The method according to claim 4 or 5, Data is transmitted and received between the virtual disk and the network storage using a block-based protocol, thereby directly controlling data blocks stored in the network storage at the user computer. The method of claim 26 or 27, The local disk further comprises a second storage unit used inside the user computer rather than being used as a cache for the virtual disk. The method of claim 26 or 27, And data is transmitted and received between the virtual disk and the network storage using a block-based protocol, thereby directly controlling data blocks stored in the network storage at the user computer.

Images