Apparatus and method for synchronizing virtual machine

Abstract

Disclosed herein are an apparatus and method for synchronizing a virtual machine. The apparatus includes a distributed image server and a virtual machine operation management unit. The distributed image server includes one or more servers distributed across a network, transfers a virtual machine image to a user using the servers, and synchronizes the virtual machine image. The virtual machine operation management unit provides a virtual machine management program so that the virtual machine image for the user can be executed on a terminal, used by the user, regardless of a location of the user.

1 . An apparatus for synchronizing a virtual machine, comprising:
 a distributed image server configured to include one or more servers distributed across a network, to transfer a virtual machine image to a user using the servers, and to synchronize the virtual machine image; and   a virtual machine operation management unit configured to provide a virtual machine management program so that the virtual machine image for the user can be executed on a terminal, used by the user, regardless of a location of the user.   
     
     
         2 . The apparatus as set forth in  claim 1 , wherein the distributed image server updates the virtual machine image with a copy-on-write (COW) image, into which a basic image of the virtual machine image has been changed, so as to synchronize the virtual machine image. 
     
     
         3 . The apparatus as set forth in  claim 2 , wherein the distributed image server transfers the virtual machine image using a server that has been selected from among the servers, distributed across the network, using bandwidth and delay time as criteria for the selection. 
     
     
         4 . The apparatus as set forth in  claim 2 , wherein the virtual machine management program comprises a distributed synchronization module for dividing the virtual machine image into the basic image and the COW image and transferring the COW image to the distributed image server. 
     
     
         5 . The apparatus as set forth in  claim 4 , wherein the virtual machine management program comprises a hypervisor module for executing a virtual operating system (OS) on the terminal using the basic image and the COW image. 
     
     
         6 . The apparatus as set forth in  claim 5 , wherein the virtual machine management program comprises a virtual machine image management module for performing management so that the basic image can be maintained in the terminal and requesting that the COW image be transferred to the distributed image servers using the distributed synchronization module based on results of determination of whether there has been a change in the COW image. 
     
     
         7 . The apparatus as set forth in  claim 2 , wherein the virtual machine operation management unit provides the virtual machine management program to a second terminal when the user has moved from a first terminal to the second terminal. 
     
     
         8 . The apparatus as set forth in  claim 7 , wherein the distributed image server receives the COW image from the first terminal using the virtual machine management program, and then updates the virtual machine image with the COW image. 
     
     
         9 . The apparatus as set forth in  claim 8 , wherein the distributed image server transfers the virtual machine image updated with the COW image to the second terminal, thereby maintaining synchronization. 
     
     
         10 . The apparatus as set forth in  claim 2 , wherein the distributed image server transfers the virtual machine image using the servers, distributed across the network, in a distributed fashion. 
     
     
         11 . A method of synchronizing a virtual machine, comprising:
 providing a virtual machine management program to a terminal to which a user has moved over a network;   one or more servers distributed across the network transferring a virtual machine image to the terminal using the virtual machine management program;   receiving a COW image, into which a basic image of the virtual machine image has been changed, from the terminal; and   updating the virtual machine image with the COW image.   
     
     
         12 . The method as set forth in  claim 11 , further comprising:
 if the user who had used the terminal has moved to another terminal, providing the virtual machine management program to the latter terminal; and   transferring the virtual machine image, updated with the COW image, to the latter terminal using the virtual machine management program, thereby maintaining synchronization.   
     
     
         13 . The method as set forth in  claim 11 , wherein the transferring a virtual machine image to the terminal comprises:
 selecting a first server from among the servers, distributed across the network, using bandwidth and delay time as criteria for selection; and   transferring the virtual machine image using the first server.   
     
     
         14 . The method as set forth in  claim 11 , wherein the virtual machine management program comprises:
 a distributed synchronization module for dividing the virtual machine image into the basic image and the COW image and transferring the COW image;   a hypervisor module for executing a virtual OS on the terminal using the basic image and the COW image; and   a virtual machine image management module for performing management so that the basic image can be maintained in the terminal and requesting that the COW image be transferred using the distributed synchronization module based on results of determination of whether there has been a change in the COW image.   
     
     
         15 . The method as set forth in  claim 11 , wherein the transferring a virtual machine image to the terminal comprises transferring the virtual machine image to the terminal using the distributed synchronization module. 
     
     
         16 . The method as set forth in  claim 11 , wherein the receiving a COW image, into which a basic image of the virtual machine image has been changed, from the terminal comprises receiving the COW image, transferred by the distributed synchronization module, based on results of determination of whether there has been a change in the COW image. 
     
     
         17 . The method as set forth in  claim 11 , wherein the transferring a virtual machine image to the terminal comprises transferring the virtual machine image using the servers, distributed across the network, in a distributed fashion.