System and method for online data migration

1. A method of changing storage drive contents, comprising:

installing a virtual storage driver in a computer system, wherein the virtual storage driver redirects access requests directed to a main storage of the computer system to one of the main storage and a temporary storage;

copying files from the main storage to the temporary storage;

restoring files from a source storage into the main storage by overwriting corresponding files in the main storage; and

redirecting, to the temporary storage, requests for access directed to files of the main storage that have been copied to the temporary storage.

2. The method of claim 1 , wherein copying the files from the main storage to the temporary storage is a background process.

3. The method of claim 1 , wherein restoring the files from the source storage into files of the main storage is a background process.

4. The method of claim 1 , further comprising hiding the temporary storage from an operating system of the computer system.

5. The method of claim 1 , wherein the main storage and the temporary storage share partitions of the same physical storage drive.

6. The method of claim 5 , wherein free blocks of the physical storage drive are used as blocks of the temporary storage.

7. The method of claim 6 , wherein blocks are assigned to the temporary storage on demand.

8. The method of claim 6 , further comprising copying blocks of the temporary storage back to corresponding blocks of the main storage if there are no free blocks available in the main storage.

9. The method of claim 5 , further comprising using blocks of different drives as blocks of the temporary storage if the storage drive contains an insufficient number of free blocks.

10. The method of claim 1 , wherein the virtual storage represents at least a partition of the disk drive, and

wherein blocks of the temporary storage are hidden on a top level of an operating system of the computer system.

11. The method of claim 1 , further comprising dividing a physical storage drive into the main storage, the temporary storage and a residual storage area;

wherein blocks of the residual storage area are available for the access requests.

12. The method of claim 1 , wherein the temporary storage is implemented as any of a RAM, a DVD-RAM, and a hard disk drive.

13. The method of claim 1 , further comprising booting another operating system to replace an operating system of the computer system, after finishing substituting storage drive content.

14. The method of claim 1 , further comprising storing, in the source storage, an earlier state of the main storage.

15. A system for changing storage drive contents comprising:

a computer system having a main storage, a temporary storage, and a source storage;

a virtual storage driver installed into an operating system of a computer, wherein the virtual storage driver redirects access requests to a main storage to one of the main storage and a temporary storage; and

a background process running on the computer system that copies files from the main storage to the temporary storage and that restores files from a source storage into the main storage by overwriting corresponding files in the main storage,

wherein the requests for access to files of the main storage that have been copied to the temporary storage are redirected to the temporary storage.

16. The system of claim 15 , wherein the temporary storage is hidden from the operating system.

17. The system of claim 15 , wherein the main storage and the temporary storage share partitions of the same physical storage drive.

18. The system of claim 15 , wherein free blocks of the physical storage drive are used as blocks of the temporary storage.

19. The system of claim 18 , wherein blocks are assigned to the temporary storage in succession.

20. A computer program product for changing storage drive contents, the computer program product comprising a computer useable medium having computer program logic recorded thereon for controlling at least one processor, the computer program logic comprising:

computer program code means for installing a virtual storage driver in a computer system, wherein the virtual storage driver redirects access requests directed to a main storage of the computer system to one of the main storage and a temporary storage;

computer program code means for copying files from the main storage to the temporary storage;

computer program code means for restoring files from a source storage into the main storage by overwriting corresponding files in the main storage; and

computer program code means for redirecting, to the temporary storage, requests for access directed to files of the main storage that have been copied to the temporary storage.