Use of virtual targets for preparing and servicing requests for server-free data transfer operations

• US 20040177130A1
• Filed: 03/07/2003
• Published: 09/09/2004
• Est. Priority Date: 03/07/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Chambliss, David D., Lay, Jeou-Rong
• Granted Patent: US 7,461,131 B2
• Time in Patent Office: Days
• US Class Current: 709/219
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A system and method are disclosed for utilizing virtual targets and abstract copy orders in preparing and servicing requests for server-free data transfer operations in a data storage network. The abstract copy orders represent data transfers between virtual targets and real devices. They allow source target copy orders to be prepared separately from destination target copy orders. The abstract copy orders may then be converted into concrete copy orders involving only real device targets for execution by a data mover that implements the server-free data transfer operations.

Claims

1. A system for implementing server-free data transfers between data storage devices in a data storage network in cooperation with a data mover in the network, comprising:

one or more abstract copy order generators adapted to generate abstract copy orders representing data transfers involving virtual targets; and

a concrete copy order generator adapted to convert abstract copy orders into concrete copy orders involving only real device targets for execution by said data mover;

whereby abstract copy orders involving real source targets can be prepared separately from abstract copy orders involving real destination targets and thereafter merged by said concrete copy order generator.

2. A system in accordance with claim 1 wherein said virtual targets are virtual FIFOs.

3. A system in accordance with claim 1 wherein said abstract copy orders are data transfer requests that specify (a) a source target and a destination target with at least one of said targets being virtual, (b) data locating information as necessary to locate said data on said source or destination target if either is real, and (c) data size information.

4. A system in accordance with claim 3 wherein said concrete copy orders are SCSI-3 extended copy command segment descriptors.

5. A system in accordance with claim 1 wherein said concrete copy order generator is adapted to convert abstract copy orders into concrete copy orders by merging pairs of abstract copy orders that reference a common virtual target along with respective real source and destination targets so that for each abstract copy order pair said real source target is combined with said real destination target to form a concrete copy order.

6. A system in accordance with claim 1 wherein said concrete copy order generator is adapted to convert abstract copy orders to concrete copy orders by grouping abstract copy orders involving a common virtual target into supplier and consumer lists, and merging pairs of abstract copy orders at the head of each list so that a real source target associated with one abstract copy order of a pair is linked to a real destination target associated with another abstract copy order of said pair.

7. A system in accordance with claim 1 wherein said abstract copy order generator is adapted to generate inter-virtual target abstract copy orders involving data transfers between virtual source and destination targets.

8. A system in accordance with claim 7 wherein said inter-virtual target abstract copy orders are used to accommodate data reordering or inline data insertion when implementing server-free data transfers.

9. A system in accordance with claim 7 wherein said concrete copy order generator is adapted to collapse each of said inter-virtual target abstract copy orders into an abstract copy order supplying data from a real source target to said source virtual target with an abstract copy order providing data from said destination virtual target to a real destination target.

10. A system in accordance with claim 1 wherein said concrete copy order generator is adapted to divide said abstract copy orders into separate abstract copy orders involving data transfers of smaller size in order to accommodate data deadlock conditions.

11. A system in accordance with claim 1 wherein said concrete copy order generator is adapted to generate data buffer commands for said data mover to buffer data until a data transfer to a real destination target can be performed that will allow an abstract copy order specifying said real destination target to be eliminated.

12. A method for implementing server-free data transfers between data storage devices in a data storage network in cooperation with a data mover in the network, comprising:

generating abstract copy orders representing data transfers involving virtual targets; and

converting said abstract copy orders into concrete copy orders involving only real device targets for execution by said data mover;

whereby abstract copy orders involving real source targets can be prepared separately from abstract copy orders involving real destination targets and thereafter merged into said concrete copy orders.

13. A method in accordance with claim 12 wherein said virtual targets are virtual FIFOs.

14. A method in accordance with claim 12 wherein said abstract copy orders are data transfer requests that specify (a) a source target and a destination target with at least one of said targets being virtual, (b) data locating information as necessary to locate said data on said source or destination target if either is real, and (c) data size information.

15. A method in accordance with claim 14 wherein said concrete copy orders are SCSI-3 extended copy command segment descriptors.

16. A method in accordance with claim 12 wherein said abstract copy orders are converted into concrete copy orders by merging pairs of abstract copy orders that reference a common virtual target along with respective real source and destination targets so that for each abstract copy order pair said real source target is combined with said real destination target to form a concrete copy order.

17. A method in accordance with claim 12 wherein said abstract copy orders are converted to concrete copy orders by grouping abstract copy orders involving a common virtual target into supplier and consumer lists, and merging pairs of abstract copy orders at the head of each list so that a real source target associated with one abstract copy order of a pair is linked to a real destination target associated with another abstract copy order of said pair.

18. A method in accordance with claim 12 further including generating inter-virtual target abstract copy orders involving data transfers between virtual source and destination targets.

19. A method in accordance with claim 18 wherein said inter-virtual target abstract copy orders are used to accommodate data reordering or inline data insertion when implementing server-free data transfers.

20. A method in accordance with claim 18 further including collapsing each of said inter-virtual target abstract copy orders into an abstract copy order supplying data from a real source target to said source virtual target with an abstract copy order providing data from said destination virtual target to a real destination target.

21. A method in accordance with claim 12 further including dividing said abstract copy orders into separate abstract copy orders involving data transfers of smaller size in order to accommodate data deadlock conditions.

22. A method in accordance with claim 12 further including generating data buffer commands for said data mover to buffer data until a data transfer to a real destination target can be performed that will allow an abstract copy order specifying said real destination target to be eliminated.

23. A storage manager server for implementing server-free data transfers between data storage devices in a data storage network in cooperation with a data mover in the network, comprising:

abstract copy order generating means for generating abstract copy orders representing data transfers involving virtual targets; and

concrete copy order generating means for converting abstract copy orders into concrete copy orders involving only real device targets for execution by said data mover;

whereby abstract copy orders involving real source targets can be prepared separately from abstract copy orders involving real destination targets and thereafter merged by said concrete copy order generating means.

24. A storage manager server in accordance with claim 23 wherein said virtual targets are virtual FIFOs.

25. A storage manager server in accordance with claim 23 wherein said abstract copy orders are data transfer requests that specify (a) a source target and a destination target with at least one of said targets being virtual, (b) data locating information as necessary to locate said data on said source or destination target if either is real, and (c) data size information.

26. A storage manager server in accordance with claim 25 wherein said concrete copy orders are SCSI-3 extended copy command segment descriptors.

27. A storage manager server in accordance with claim 23 wherein said concrete copy order generating means includes means for merging pairs of abstract copy orders that reference a common virtual target along with respective real source and destination targets so that for each abstract copy order pair said real source target is combined with said real destination target to form a concrete copy order.

28. A storage manager server in accordance with claim 23 wherein said concrete copy order generating means includes means for grouping abstract copy orders involving a common virtual target into supplier and consumer lists, and means for merging pairs of abstract copy orders at the head of each list so that a real source target associated with one abstract copy order of a pair is linked to a real destination target associated with another abstract copy order of said pair.

29. A storage manager server in accordance with claim 23 wherein said abstract copy order generating means includes means for generating inter-virtual target abstract copy orders involving data transfers between virtual source and destination targets.

30. A storage manager server in accordance with claim 29 wherein said inter-virtual target abstract copy orders are used to accommodate data reordering or inline data insertion when implementing server-free data transfers.

31. A storage manager server in accordance with claim 29 wherein said concrete copy order generating means includes means for collapsing each of said inter-virtual target abstract copy orders into an abstract copy order supplying data from a real source target to said source virtual target with an abstract copy order providing data from said destination virtual target to a real destination target.

32. A storage manager server in accordance with claim 23 wherein said concrete copy order generating means includes means for dividing said abstract copy orders into separate abstract copy orders involving data transfers of smaller size in order to accommodate data deadlock conditions.

33. A storage manager server in accordance with claim 23 wherein said concrete copy order generating means includes means for generating data buffer commands for said data mover to buffer data until a data transfer to a real destination target can be performed that will allow an abstract copy order specifying said real destination target to be eliminated.

34. A computer program product for implementing server-free data transfers between data storage devices in a data storage network in cooperation with a data mover in the network, comprising:

one or more data storage media;

abstract copy order generating means recorded on said data storage media for generating abstract copy orders representing data transfers involving virtual targets; and

concrete copy order generating means recorded on said data storage media for converting abstract copy orders into concrete copy orders involving only real device targets for execution by said data mover;

whereby abstract copy orders involving real source targets can be prepared separately from abstract copy orders involving real destination targets and thereafter merged by said concrete copy order generating means.

35. A computer program product in accordance with claim 34 wherein said virtual targets are virtual FIFOs.

36. A computer program product in accordance with claim 34 wherein said abstract copy orders are data transfer requests that specify (a) a source target and a destination target with at least one of said targets being virtual, (b) data locating information as necessary to locate said data on said source or destination target if either is real, (c) and data size information.

37. A computer program product in accordance with claim 36 wherein said concrete copy orders are SCSI-3 extended copy command segment descriptors.

38. A computer program product in accordance with claim 34 wherein said concrete copy order generating means includes means recorded on said data storage media for merging pairs of abstract copy orders that reference a common virtual target along with respective real source and destination targets so that for each abstract copy order pair said real source target is combined with said real destination target to form a concrete copy order.

39. A computer program product in accordance with claim 34 wherein said concrete copy order generating means includes means recorded on said data storage media for grouping abstract copy orders involving a common virtual target into supplier and consumer lists, and means recorded on said data storage media for merging pairs of abstract copy orders at the head of each list so that a real source target associated with one abstract copy order of a pair is linked to a real destination target associated with another abstract copy order of said pair.

40. A computer program product in accordance with claim 34 wherein said abstract copy order generating means includes means recorded on said data storage media for generating inter-virtual target abstract copy orders involving data transfers between virtual source and destination targets.

41. A computer program product in accordance with claim 40 wherein said inter-virtual target abstract copy orders are used to accommodate data reordering or inline data insertion when implementing server-free data transfers.

42. A computer program product in accordance with claim 40 wherein said concrete copy order generating means includes means recorded on said data storage media for collapsing each of said inter-virtual target abstract copy orders into an abstract copy order supplying data from a real source target to said source virtual target with an abstract copy order providing data from said destination virtual target to a real destination target.

43. A computer program product in accordance with claim 34 wherein said concrete copy order generating means includes means recorded on said data storage media for dividing said abstract copy orders into separate abstract copy orders involving data transfers of smaller size in order to accommodate data deadlock conditions.

44. A computer program product in accordance with claim 34 wherein said concrete copy order generating means includes means recorded on said data storage media for generating data buffer commands for said data mover to buffer data until a data transfer to a real destination target can be performed that will allow an abstract copy order specifying said real destination target to be eliminated.