WO2007011164A1

WO2007011164A1 - Virtual storage system and method for managementing virtual storage based on ad-hoc network

Info

Publication number: WO2007011164A1
Application number: PCT/KR2006/002837
Authority: WO
Inventors: Bo-Young Kang; Young-Jin Nam; Dae-Wha Seo
Original assignee: Kyungpook National University Industry-Academic Cooperation Foundation
Priority date: 2005-07-21
Filing date: 2006-07-19
Publication date: 2007-01-25

Abstract

A virtual storage system and a method therefore based on an ad-hoc network. The virtual storage system includes: a virtual storage management server which implements one virtual storage constructed with storage devices of a plurality of portable multimedia players (PMPs) on a network and manages the virtual storage; a database server which stores and manages information on a file stored and managed in an internal storage device of each of the portable multimedia players constituting the virtual storage constructed by the virtual storage management server; and the portable multimedia players, each of which executes a storage node program for storing data transmitted from the virtual storage management server to the portable multimedia player and managing the data and a user program for allowing the virtual storage of the virtual storage management server to be used. Accordingly, in the virtual storage system, the storage devices mounted in the portable multimedia players on the network can be used and managed as a single virtual storage.

Description

[DESCRIPTION]

[invention Title]

VIRTUAL STORAGE SYSTEM AND METHOD FOR MANAGEMENTING VIRTUAL STORAGE BASED ON AD-HOC NETWORK

[Technical Field]

The present invention relates to a virtual storage system and a virtual storage managing method, and more particularly, to a virtual storage system using a universal plug and play (UPnP) technique based on a mobile ad-hoc network and a method of inputting and outputting files by using the virtual storage.

[Background Art]

A portable multimedia player (PMP) is called a next- generation portable convergence device because it has a basic structure similar to a conventional MP3 player but it additionally has a function of reproducing video as well as digital camera functions unlike the conventional MP3 player. Furthermore, the PMP can store and reproduce MP3 files and images so that it can be used as an electronic photo album containing digital photographs taken by a digital camera. Moreover, the PMP has various additional functions such as video recording, schedule management, Internet connection, etc. The PMP having such various functions should have an internet memory unit (i.e. a storage) having a predetermined capacity.

On the other hand, it has been known in the related art that a universal plug and play (UPnP) technology developed by Intel® Corporation is a standard technology for accommodating home networking. When such apparatuses as personal computers, peripherals, intelligent electronic appliances, wireless apparatuses are connected to a network, these apparatuses can be automatically recognized by using protocols for the Internet and WEB.

In particular, a UPnP AV system is based on the UPnP technology and includes a control point, a media server, a media renderer. In the UPnP AV system, when a user selects contents of the media server and the media renderer though a user interface, the selected contents of the media server is directly transmitted to the associated media renderer, so that the contents are reproduced in the media renderer.

However, even in case of apparatuses having the UPnP function, when an apparatus serving as the media server transmits the contents to an apparatus serving as the media renderer, the capacity of memory in the media server is limited, so that there is a limitation to a size of the contents stored in the media server. In addition, since the memories included the entire apparatuses connected to the network cannot be integrally managed, large-sized contents cannot be stored, and the entire memories cannot be effectively managed.

[Disclosure] [Technical Problem] The present invention provides a virtual storage system using storage devices included in an apparatus using a UPnP technique based on a mobile ad-hoc network as a virtual storage.

The present invention also provides a virtual storage managing method of managing a virtual storage implemented in the virtual storage system, capable of storing, updating, removing, and reading a specific file in the virtual storage.

[Technical Solution]

According to an aspect of the present invention, there is provided a virtual storage system comprising: a plurality of apparatuses on a network; a virtual storage management server which constructs one or more storage devices provided to the apparatuses into one virtual storage and manages the virtual storage; and a database server which stores and manages information on files stored in the storage devices of the apparatuses constituting the virtual storage constructed by the virtual storage management server, wherein each of the apparatuses includes a storage node program which stores and manages the data transmitted from the virtual storage management server in the storage device and a user program which allows the virtual storage of the virtual storage management server to be used and the programs are executed, so that the storage devices provided to the apparatuses on the network is used as one virtual storage.

In the aforementioned aspect of the invention, the virtual storage management server of the virtual storage system distributes and stores a specific file into the storage devices of a plurality of the mobile apparatuses constituting the virtual storage.

In addition, the virtual storage management server of the virtual storage system may generate and manage a storage node table, and the storage node table may record information on the mobile apparatuses registered as the storage nodes. In addition, the database server may include an object ID list of the file, and the object ID list may include strip unit IDs constituting the file and storage node information storing the strip unit IDs.

In addition, the mobile apparatuses of the virtual storage system may be portable multimedia players.

According to another aspect of the present invention, there is provided a virtual storage managing method of constructing one virtual storage by a virtual storage virtual storage management server cooperating with an external database server and a plurality of apparatuses on a network and managing the virtual storage, the virtual storage managing method comprising steps of: (a) in the virtual storage management server, searching for the apparatuses on the network; (b) registering information on the searched apparatuses in a storage node table of the virtual storage management server; (c) receiving a file storing request message and a to-be-stored file from an apparatus on the network; (d) allocating a file ID to the received file and transmitting the file ID to the database server to register the file ID; (e) dividing the file into strip units; (f) selecting from the storage node table storage nodes in which the divided strip units are to be stored; (g) transmitting the strip units to the respective selected storage nodes; (h) receiving from the storage nodes object IDs generated after the associated strip units are normally stored ; (i) collecting the object IDs received from the storage nodes to generate an object ID list; and (j) storing the generated object ID list in the database server, wherein the file is stored in the virtual storage.

In the aforementioned aspect of the invention, the virtual storage managing method may comprise steps of: (k) receiving a file updating request message, a to-be-updated file ID, and a to-be-updated file from an apparatus on the network; (1) receiving an object ID list of the updating- requested file ID from the database server; (m) dividing the received file into strip units; (n) selecting from the storage node table storage nodes in which the divided strip units are to be stored; (o) transmitting the strip units to the respective selected storage nodes; (p) receiving from the storage nodes the object IDs generated after the associated strip units are normally stored; (q) collecting the object IDs received from the storage nodes and updating the object ID list; and (r) storing the updated object ID list in the database server, wherein the file is updated on the virtual storage.

In addition, virtual storage managing method may comprises steps of: (k) receiving a file removing request message and a to-be-removed file ID from an apparatus on the network; (1) receiving an object ID list of the file ID from the database server; (m) extracting storage node ID information on the strip units from the object ID list; (n) transmitting an object removing request message to the storage nodes corresponding to the extracted storage node IDs; (o) receiving an object removing confirmation messages from the storage nodes; and (p) transmitting a removing request message for the object ID list of the associated file ID to the database server, wherein the specific file stored in the virtual storage is removed.

In addition, virtual storage managing method may comprises steps of: (k) receiving a file reading request message and a file ID from an apparatus on the network; (1) receiving an object ID list of the file ID from the database server; (m) extracting storage node ID information on the storage nodes in which the strip units are stored from the object ID list; (n) transmitting an object reading request message to the storage nodes corresponding to the extracted storage node IDs; (o) detecting strip units from the messages received from the storage nodes, collecting the detected strip units, and rearranging the strip units to generates one file; and (p) transmitting the generated file to the requesting apparatus, wherein the specific file is read from the virtual storage.

[Advantageous Effects]

According to the present invention, storage devices built in mobile apparatuses distributed on a network can be used as one virtual storage. Therefore, a user can use such a large-sized virtual storage as a storage device of the user's mobile apparatus freely. In addition, a user can use multimedia contents stored in other users' mobile apparatuses freely.

Particularly, the virtual storage can be constructed in a corporate, an institute, or a specific group as well as between personal users, so that information can be easily and speedily shared. As a result, a storage space can be saved.

In addition, according to the present invention, since a virtual storage managing system is based on an ad-hoc network, before a virtual storage management server searches for mobile apparatuses, the mobile apparatuses, the virtual storage management server, and a database server on the network can autonomously and promptly construct a network based on the ad-hoc network without assistance of a fixed network.

[Description of Drawings]

FIG. 1 is a schematic block diagram illustrating a virtual storage system according to a preferred embodiment of the present invention.

F]G. 2 is a flowchart illustrating a sequence of steps of generating a storage node table in a virtual storage management server of the virtual storage system the preferred embodiment of the present invention.

F]G. 3 is a flowchart illustrating a sequence of steps of storing a specific file in a virtual storage of the virtual storage system the preferred embodiment of the present invention.

F]G. 4 is a flowchart illustrating a sequence of steps of updating the specific file stored in the virtual storage of the virtual storage system the preferred embodiment of the present invention.

F]G. 5 is a flowchart illustrating a sequence of steps of removing the specific file stored in the virtual storage of the virtual storage system the preferred embodiment of the present invention. FIG. 6 is a flowchart illustrating a sequence of steps of reading the specific file stored in the virtual storage of the virtual storage system the preferred embodiment of the present invention.

[Best Mode]

Hereinafter, structures and operations of a virtual storage system according to preferred embodiments of the present invention will be described with reference to the accompanying drawings . FlG. 1 is a schematic constructional view illustrating a virtual storage system 10 according to the preferred embodiment of the present invention. Referring to FIG. 1, the virtual storage system 10 is constructed with a virtual storage management server 100, a database server 110, and at least one mobile apparatus 120 including a storage node program 122 and a user program 124. Hereinafter, operations of the aforementioned components will be described in detail.

The virtual storage management server 100 constructs a single virtual storage with storage devices of a plurality of mobile apparatuses on a network and manages the virtual storage. In addition, the virtual storage management server generates a storage node table 102 containing information on the mobile apparatuses constituting the virtual storage and manages the storage node table. The storage node table 102 includes storage node IDs as identification information on the storage devices, address information on the mobile apparatuses used as the storage nodes, and information on availability of the storage devices of the associated storage nodes . The virtual storage management server 100 distributes and stores one specific file into the storage devices of a plurality of the mobile apparatuses constituting one virtual storage and updates, removes, and reads the distributed specific file. The operations of storing, updating, removing, and reading the file in the virtual storage managing system will be described later in detail.

The database server 110 stores a file information managing table for the file stored in the virtual storage and manages the file information managing table. The file information managing table includes a file ID as file identification information and an object ID list of the file. The object ID list includes information on strip unit IDs constituting the associated file and the storage node IDs storing the strip units. Each mobile apparatus 120 includes the storage node program 122 which stores data transmitted from the virtual storage management server in an internal storage device and manages the data and the user program 124 which allows the virtual storage of the virtual storage management server to be used. The storage node program 122 of the mobile apparatus analyzes a request message transmitted from the virtual storage management server 100 and performs functions of registering storage nodes and generating, removing, updating, and reading an object.

Firstly, when the request message transmitted from the virtual storage management server is a "storage node registering" request message, a registering response message including identification information, path information, and information on a writable storage space of the storage device of the mobile apparatus is transmitted to the virtual storage management server, so that the mobile apparatus is registered in the storage node table of the virtual storage management server. When the request message transmitted from the virtual storage management server is an "object generating" request message, the strip unit data are extracted from the request message, the strip unit ID is allocated to the extracted strip unit data and stored in a memory. After that, the object ID including the strip unit ID and the storage node ID is generated, and an object generating response message including the object ID and information on the writable storage space of the storage device is transmitted to the virtual storage management server 100. When the request message transmitted from the virtual storage management server is an "object removing" request message, the strip unit ID is extracted from the request message, and the strip unit corresponding to the extracted strip unit ID is removed. After that, an object removing response message including the removed object ID and information on the writable storage space of the storage device is transmitted to the virtual storage management server.

When the request message transmitted from the virtual storage management server is an "object updating" request message, the to-be-updated strip unit ID and strip unit data are extracted from the request message, and the previously stored strip unit data corresponding to the strip unit ID are removed and updated by the extracted strip unit data. After that, an object updating response message including the updated object ID and information on the writable storage space of the storage device is transmitted to the virtual storage management server.

When the request message transmitted from the virtual storage management server is an "object reading" request message, the strip unit ID is extracted from the request message, and the strip unit data corresponding to the strip unit ID are read from the memory. After that, an object reading response message including the read strip unit data and the object ID is transmitted to the virtual storage management server. The user program 124 of the mobile apparatus provides a user interface so as to allow the mobile apparatus to access to the virtual storage management server 100 to store a specific file to the virtual storage and retrieve, read, remove, and update the specific file stored in the virtual storage.

Now, a sequence of steps of generating the storage node table 102 in the virtual storage management server 100 of the virtual storage system 10 according to the preferred embodiment of the present invention are described with reference to FIG 2.

Firstly, the virtual storage management server 100 searches for the database server 110 on the network (Step 200) . The database server transmits the registering request message to the virtual storage management server (Step 210) , and the virtual storage management server performs an authentication process on the database server (Step 220) . When the authentication process on the database server is completed, an authentication confirmation message to the database server (Step 230) , and in response thereto, the database server transmits a confirmation message (Step 240) .

Next, the virtual storage management server 100 loads the storage node table storing the information on the mobile apparatuses on the network which perform a function of a storage node (Step 250) . The storage node table includes storage node identification information ID, address information on the mobile apparatuses used as the storage nodes, and information on writable storage spaces of the storage devices of the associated storage nodes.

Next, the virtual storage management server 100 searches for the storage nodes on the network (Step 260) , and requests for registering the searched storage node as a virtual storage (Step 270) . When the authentication process on the storage node is performed and completed, the storage node identification information is allocated to the storage node, and the storage node is registered in the storage node table (Step 280) . The virtual storage management server transmits to the storage node a confirmation message confirming that the storage node is registered as the virtual storage (Step 290) , and the storage node transmits a confirmation message to the virtual storage management server (Step 292) .

Through the aforementioned steps, the storage device of the mobile apparatus on the network can be used as a virtual storage. Now, a sequence of steps of storing the specific file in the virtual storage in the virtual storage system according to the preferred embodiment of the present invention are described with reference to FIG 3.

Firstly, a mobile apparatus in which the user program is executed transmits a file storing request message and a to-be-stored file to the virtual storage management server (Step 300) . The virtual storage management server receiving the file storing request message allocates file identification information on the associated file (Step 305) , and after that, transmits the file identification information to the database server (Step 310) . The database server additionally registers the transmitted information in the database (Step 315) .

Next, the virtual storage management server divides the file into 256KB-sized strip units and selects writable storage nodes among the storage nodes registered in the storage node table (Step 320) . Here, as an example of a method of selecting the writable storage node, a round-robin method is used. Next, an object generating request message together with the information on the divided strip units are transmitted to the selected storage nodes (Step 330) .

The storage node which receives the object generating request message from the virtual storage management server extracts strip unit data from the object generating request message (Step 340) and allocates the strip unit ID to the extracted strip unit (Step 342) . Next, a space for storing the strip unit is determined, and after that, the strip unit is stored (Step 344) . Next, the object ID including the strip unit ID and the storage node ID is generated (Step 346) , and an object generating response message including the generated object ID and information on a writable storage space is generated and transmitted to the virtual storage management server (Step 348) .

The virtual storage management server receives the object generating response message, updates a writable storage space field of the storage node table according to the received message, and generates an object ID list (Step

350) . The object ID list includes an object ID which the virtual storage management server extracts from the object generating response messages received from a plurality of the storage nodes.

The generated object ID list is transmitted to the database server (Step 360) . The database server additionally registers the transmitted object ID list (Step 365) and transmits a confirmation message to the virtual storage management server (Step 370) .

Next, the virtual storage management server transmits to the mobile apparatus which requests for storing the file a message that the file writing is completed (Step 380) .

Now, a sequence of steps of updating the specific file stored in the virtual storage of the virtual storage system according to the preferred embodiment of the present invention are described with reference to FIG 4.

Firstly, a mobile apparatus in which the user program is executed transmits a file updating request message and a to-be-updated file to the virtual storage management server

(Step 400) . The virtual storage management server receiving the file updating request message requests for the file ID and the object ID list to the database server (Step 410) and receives the transmitted the file ID and the object ID list (Step 415) . Next, the virtual storage management server divides the file into 256KB-sized strip units and selects writable storage node among the storage nodes registered in the storage node table (Step 420) . Here, as an example of a method of selecting the writable storage node, a round-robin method is used. Next, an object updating request message together with the data information on the divided strip unit is transmitted to the selected storage nodes (Step 430) .

The storage node which receives the object updating request message from the virtual storage management server extracts the strip unit data from the object updating request message (Step 440) and the strip unit ID from the object ID

(Step 442) . Next, a space for storing the strip unit is determined, and after that, the strip unit data is stored in the determined space (Step 444) . Next, an object updating response message including the object ID and information on a writable storage space of the storage device is generated and transmitted to the virtual storage management server (Step 446) .

The virtual storage management server receives the object updating response message and updates a writable storage space field of the storage node table according to the received message (Step 450) . Next, the updated object ID list is transmitted to the database server (Step 460) . The database server updates the transmitted object ID list (Step 465) and transmits a updating confirmation message to the virtual storage management server (Step 470) .

Next, the virtual storage management server transmits to the mobile apparatus which requests for updating the file a message that the file updating is completed (Step 480) .

Now, a sequence of steps of removing the specific file stored in the virtual storage of the virtual storage system according to the preferred embodiment of the present invention are described with reference to FIG 5.

Firstly, a mobile apparatus in which the user program is executed transmits a file removing request message and information on a to-be-removed file to the virtual storage management server (Step 500) . The virtual storage management server receiving the file removing request message requests for the object ID list for the associated file to the database server (Step 510) and receives the object ID list (Step 515) .

The virtual storage management server extracts the storage node ID from the transmitted object ID list and selects the associated storage nodes with reference to the storage node table (Step 520) and, after that, transmits an object removing request message to the selected storage nodes (Step 530) . The storage node which receives the object removing request message from the virtual storage management server extracts the strip unit ID from the object removing request message (Step 540) and searches for the extracted strip unit ID and removes the corresponding strip unit ID from the storage space (Step 542) . Next, an object removing response message including the object ID and information on the writable storage space of the storage device is generated and transmitted to the virtual storage management server (Step 548).

The virtual storage management server receives the object removing response message and updates the writable storage space field of the storage node table according to the received message (Step 550) and requests for removing the information on the associated file ID to the database server (Step 560) .

The database server removes the information on the file ID according to the file removing request (Step 565) and transmits a removing confirmation message to the virtual storage management server (Step 570) .

Next, the virtual storage management server transmits to the mobile apparatus requesting for removing the file a message that the file removing is completed (Step 580) .

Now, a sequence of steps of reading the specific file stored in the virtual storage of the virtual storage system according to the preferred embodiment of the present invention are described with reference to FIG 6.

A mobile apparatus in which the user program is executed transmits a file reading request message for specific file to the virtual storage management server (Step 600) . The virtual storage management server receiving the file reading request message requests for the object ID list for the associated file ID to the database server (Step 610) and receives the transmitted object ID list (Step 615) . Next, the virtual storage management server extracts the storage node ID from the object ID and searches for an address of the storage node ID by using the storage node table (Step 620) and transmits the object reading request message to the associated storage nodes (Step 630) . The storage node receiving the object reading request message from the virtual storage management server extracts the strip unit ID from the object ID and reads the strip unit from the storage space allocated to the extracted strip unit ID (Step 642) and transmits the object reading response message including the read strip unit and object ID to the virtual storage management server (Step 644) .

Next, the virtual storage management server extracts the strip unit from the object reading response message transmitted from the storage node (Step 646) . By repeating the aforementioned steps, the virtual storage management server collects the strip units and sequentially arranges the collected strip units to complete a file (Step 648) and transmits a file reading response message together with contents of the file to the mobile apparatus (Step 650) . While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The exemplary embodiments should be considered in descriptive sense only and not for purposes of limitation. Therefore, the scope of the invention is defined not by the detailed description of the invention but by the appended claims, and all differences within the scope will be construed as being included in the present invention.

[industrial Applicability]

A virtual storage system and a virtual storage managing method may be widely used for home networking based on a UPnP technology.

Claims

[CLAIMS] [Claim l]

A virtual storage system comprising: a plurality of apparatuses on a network; a virtual storage management server which constructs one or more storage devices provided to the apparatuses into a single virtual storage and manages the virtual storage; and a database server which stores and manages information on files stored in the storage devices of the apparatuses constituting the virtual storage constructed by the virtual storage management server, wherein each of the apparatuses includes a storage node program which stores and manages the data transmitted from the virtual storage management server in the storage device and a user program which allows the virtual storage to be used, and the programs are executed, so that the storage devices provided to the apparatuses on the network are used as a single virtual storage.

[Claim 2] The virtual storage system according to claim 1, wherein the virtual storage management server distributes and stores a specific file into the storage devices of a plurality of the apparatuses constituting the virtual storage.

[Claim 3]

The virtual storage system according to claim 1, wherein the virtual storage management server generates and manages a storage node table, and wherein the storage node table records identification information and path information on the apparatuses registered as the storage nodes.

[Claim 4]

The virtual storage system according to claim 1, wherein the database server includes an object ID list of the file, and wherein the object ID list includes strip unit IDs constituting the file and information on storage nodes storing the strip unit IDs.

[Claim 5]

The virtual storage system according to claim 1, wherein the apparatuses have a universal plug and play function based on a mobile ad-hoc network.

[Claim 6] The virtual storage system according to one of claims

1 to 5, wherein the apparatuses are portable multimedia players.

[Claim 7]

A virtual storage managing method of constructing one virtual storage by a virtual storage virtual storage management server cooperating with an external database server and a plurality of apparatuses on a network and managing the virtual storage, the virtual storage managing method comprising steps of:

(a) in the virtual storage management server, searching for the apparatuses on the network; (b) registering information on the searched apparatuses in a storage node table of the virtual storage management server;

(c) receiving a file storing request message and a to- be-stored file from an apparatus on the network; (d) allocating a file ID to the received file and transmitting the file ID to the database server to register the file ID;

(e) dividing the file into strip units;

(f) selecting from the storage node table storage nodes in which the divided strip units are to be stored;

(g) transmitting the strip units to the respective selected storage nodes;

(h) receiving from the storage nodes object IDs generated after the associated strip units are normally stored ; (i) collecting the object IDs received from the storage nodes to generate an object ID list; and

(j) storing the generated object ID list in the database server, wherein the file is stored in the virtual storage.

[Claim 8]

The virtual storage managing method according to claim

7, comprising steps of:

(k) receiving a file updating request message, a to- be-updated file ID, and a to-be-updated file from an apparatus on the network;

(1) receiving an object ID list of the updating- requested file ID from the database server;

(m) dividing the received file into strip units; (n) selecting storage nodes in which the divided strip units are to be stored from the storage node table;

(o) transmitting the strip units to the respective selected storage nodes;

(p) receiving from the storage nodes the object IDs generated after the associated strip units are normally stored;

(q) collecting the object IDs received from the storage nodes and updating the object ID list; and

(r) storing the updated object ID list in the database server, wherein the file is updated on the virtual storage.

[Claim 9]

The virtual storage managing method according to claim

7, comprising steps of:

(k) receiving a file removing request message and a to-be-removed file ID from an apparatus on the network;

(1) receiving an object ID list of the file ID from the database server;

(m) extracting storage node ID information on the strip units from the object ID list; (n) transmitting object removing request messages to the storage nodes corresponding to the extracted storage node IDs;

(o) receiving object removing confirmation messages from the storage nodes; and (p) transmitting a removing request message for the object ID list of the associated file ID to the database server, wherein the specific file stored in the virtual storage is removed.

[Claim 10]

The virtual storage managing method according to claim

7, comprising steps of:

(k) receiving a file reading request message and a file ID from an apparatus on the network; (1) receiving an object ID list of the file ID from the database server;

(m) extracting storage node ID information on the storage nodes in which the strip units are stored from the object ID list; (n) transmitting an object reading request message to the storage nodes corresponding to the extracted storage node IDs;

(o) detecting strip units from the messages received from the storage nodes, collecting the detected strip units, and rearranging the strip units to generates one file; and

(p) transmitting the generated file to the requesting apparatus, wherein the specific file is read from the virtual storage.

[Claim 11]

The virtual storage managing method according to one of claims 7 to 10, wherein the apparatuses have a universal plug and play function based on a mobile ad-hoc network.

[Claim 12] A recording medium for recording a storage node program executed on a mobile apparatus having a universal play and plug (UPnP) function based on an ad-hoc network, wherein the storage node program executes a sequence of steps of: (a) transmitting identification information and path information on the mobile apparatus to an external virtual storage management server according to a registering request to a storage node from the virtual storage management server and registering the mobile apparatus to a storage node table of the virtual storage management server;

(b) receiving a storing request message and strip unit data from the virtual storage management server;

(c) allocating strip unit IDs to the strip unit data, storing the strip unit data, and generating an object ID including the strip unit IDs and storage node IDs which is the identification information; and

(d) transmitting the generated object ID to the virtual storage management server, wherein a file requested by the external virtual storage management server is stored, and the mobile apparatus is allowed to operate as a storage node of a virtual storage system.

[Claim 13]

The recording medium according to claim 12, wherein the storage node program further comprises steps of:

(e) receiving a removing request message from the virtual storage management server;

(f) extracting a to-be-removed strip unit ID from the removing request message; and (g) removing the strip unit corresponding to the strip unit ID, wherein a file requested by the external virtual storage management server is removed.

[Claim 14] The recording medium according to claim 12, wherein the storage node program further comprises steps of:

(e) receiving a reading request message from the virtual storage management server;

(f) extracting a strip unit ID from the reading request message;

(g) reading the strip unit corresponding to the strip unit ID from a memory; and

(h) transmitting the read strip unit to the virtual storage management server, wherein a file requested by the external virtual storage management server is removed.

[Claim 15]

The recording medium according to one of claims 12 to

14, wherein the storage node program further comprises a step of transmitting information on a writable storage space of the storage devices to the virtual storage management server.