Computer and associated method for restoring data backed up on archive media

• US 5,926,836 A
• Filed: 12/03/1996
• Issued: 07/20/1999
• Est. Priority Date: 12/03/1996
• Status: Expired due to Term

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Blumenau, Steven M.
• Primary Examiner(s): Gossage, Glenn
• Application Number:
  US08/753,952
• Time in Patent Office: 959 Days
• Field of Search: 711/161, 711/162, 711/202, 711/203, 395/182.04, 395/182.13, 395/183.18, 371/40.1, 371/40.2
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1469 Backup restoration techniques

Abstract

A computer having restore capabilities for data backed up on archive media, the computer including a restore application which identifies the target data to be restored from the archive media and makes logical user read and write requests, an interpreter that does logical to physical mapping and maps logical user read and write requests to physical block level read and write requests, a host storage driver having a disk driver interface for receiving block level read and write requests from the interpreter, a host storage disk connected to be controlled by the host storage driver, and a restore system having a disk driver interface to the interpreter for receiving block level read requests from the interpreter, the restore system issuing instructions to read data from archive media at a block, physical level and returning the data obtained from the archive media to the interpreter.

Claims

1. A computer having restore capabilities for data backed up on archive media, said computer comprising

a restore application which identifies target data to be restored from said archive media and makes logical user read and write requests,

an interpreter that maps said logical user read and write requests to physical block level read and write requests,

a host storage driver having a disk driver interface for receiving said physical block level read and write requests from said interpreter,

a host storage disk connected to be controlled by said host storage driver, said host storage driver generating disk control signals to read and write blocks of data from said host storage disk in response to said physical block level read and write requests, and

a restore system having a disk driver interface to said interpreter for receiving the physical block level read requests from said interpreter, said restore system issuing instructions to read data from said archive media at a block, physical level and returning the data read from said archive media to said interpreter.

2. The computer of claim 1 wherein said interpreter comprises a database server application.

3. The computer of claim 1 wherein said interpreter comprises a file system of an operating system of said computer.

4. The computer of claim 3 wherein said restore application issues instructions to said file system to open an input file for said target data on said archive media, to open an output file for said target data on said host disk, and to copy the input file to said output file.

5. The computer of claim 1 wherein said restore system includes a restore driver and an archive media system, said restore driver providing said disk driver interface of said restore system and also having an operating system device driver application programming interface to said archive media system, said archive media system being implemented in user space of said computer and communicating with said archive media, said archive media being external to said computer.

6. The computer of claim 5 further comprising a restore control program that identifies the archive media on which said target data are located and communicates this information to said archive media system.

7. The computer of claim 5 wherein said archive media system and said restore application communicate via IOCTL messages.

8. The computer of claim 5 wherein said archive media system communicates with archive media comprising a tape library.

9. The computer of claim 5 wherein said archive media system has a local cache for storing data from said archive media.

10. The computer of claim 9 wherein said local cache also stores data written to it from said restore driver.

11. A computer implemented method of restoring data backed up from a computer on archive media, said method comprising

identifying target data to be restored from said archive media at a restore application on said computer,

making logical user read and write requests at said restore application to copy said target data from said archive media to a host storage disk controlled by a host storage driver,

mapping said logical user read and write requests to physical block level read and write requests at an interpreter of said computer,

receiving said physical block level read requests from said interpreter at a restore system having a disk driver interface to said interpreter, said restore system issuing instructions to read data from said archive media at a block, physical level and returning the data read from said archive media to said interpreter, and

writing the data read from said archive media on said host storage disk.

12. The method of claim 11 wherein said interpreter comprises a database server application.

13. The method of claim 11 wherein said interpreter comprises a file system of an operating system of said computer.

14. The method of claim 13 wherein said logical user read and write requests made by said restore application include instructions to said file system to open an input file for said target data on said archive media, to open an output file for said target data on said host disk, and to copy the input file to said output file.

15. The method of claim 11 wherein said restore system includes a restore driver and an archive media system, said restore driver providing said disk driver interface of said restore system and also having an operating system device driver application programming interface to said archive media system, said archive media system being implemented in user space of said computer and communicating with said archive media, said archive media being external to said computer.

16. The method of claim 15 further comprising identifying the archive media on which said target data are located and communicating this information to said archive media system using a restore control program.

17. The method of claim 15 wherein said archive media system and said restore application communicate via IOCTL messages.

18. The method of claim 15 wherein said archive media system communicates with archive media comprising a tape library.

19. The method of claim 15 further comprising storing data from said archive media in a local cache of said archive media system.

20. The method of claim 19 further comprising storing data written to said archive media system from said restore driver in said local cache.

21. A computer program for implementation on a computer to restore data backed up from said computer on archive media, said computer program residing on a computer-readable medium, said computer having

an interpreter that maps logical user read and write requests to physical block level read and write requests,

a host storage driver having a disk driver interface for receiving said physical block level read and write requests from said interpreter,

a host storage disk connected to be controlled by said host storage driver, said host storage driver generating disk control signals to read and write blocks of data from said host storage disk in response to said physical block level read and write requests,

said computer program comprising instructions causing said computer to create

a restore application which identifies target data to be restored from said archive media and makes said logical user read and write requests to said interpreter, and

a restore system having a disk driver interface to said interpreter for receiving said physical block level read requests from said interpreter, said restore system issuing instructions to read data from said archive media at a block, physical level and returning the data read from said archive media to said interpreter.

22. The computer program of claim 21 wherein said interpreter comprises a database server application.

23. The computer program of claim 21 wherein said interpreter comprises a file system of an operating system of said computer.

24. The computer program of claim 23 wherein said restore application issues instructions to said file system to open an input file for said target data on said archive media, to open an output file for said target data on said host disk, and to copy the input file to said output file.

25. The computer program of claim 21 wherein said restore system includes a restore driver and an archive media system, said restore driver providing said disk driver interface of said restore system and also having an operating system device driver application programming interface to said archive media system, said archive media system being implemented in user space of said computer and communicating with said archive media, said archive media being external to said computer.

26. The computer program of claim 25 further comprising a restore control program that identifies the archive media on which said target data are located and communicates this information to said archive media system.

27. The computer program of claim 25 wherein said archive media system and said restore application communicate via IOCTL messages.

28. The computer program of claim 25 wherein said archive media system communicates with archive media comprising a tape library.

29. The computer program of claim 25 wherein said archive media system has a local cache for storing data from said archive media.

30. The computer program of claim 29 wherein said local cache also stores data written to it from said restore driver.