System, method and apparatus for logical volume duplexing in a virtual tape system

• US 7,107,417 B2
• Filed: 08/29/2002
• Issued: 09/12/2006
• Est. Priority Date: 08/29/2002
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kishi, Gregory Tad, Peake, Jonathan Wayne, Gibble, Kevin Lee
• Primary Examiner(s): CHACE, CHRISTIAN
• Application Number:
  US10/231,345
• Publication Number:
  US 20040044830A1
• Time in Patent Office: 1,475 Days
• Field of Search: 707/10, 707/102, 707/202, 707/204, 711/4, 711/111, 711/118, 711/153, 711/161, 714/6
• US Class Current: 711/161
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0686 Libraries, e.g. tape libraries, jukebox

Abstract

A system, method, and apparatus are provided for copying a virtual volume to multiple physical volumes within a virtual tape system. The virtual tape system may include a virtual tape server (VTS), a library manager, and a plurality of tape drive units into which cartridges may be individually mounted. The virtual tape system stores virtual volumes, each of which represents a physical volume, although one or more virtual volumes are actually stored on a real physical volume. The library manager contains a volume database with a plurality of constructs and associated storage management actions. The constructs are received from a host computer connected to the VTS, but the storage management actions may be entered directly into the library manager, independently of the host. The library manager reads the management action associated with one or more constructs of a virtual volume and, along with the VTS, determines whether multiple physical copies of the virtual volume are to be made.

Claims

1. A virtual tape system configured to store data from a host on a plurality of physical volumes, the virtual tape system comprising:

means for receiving a volume of data from the host;

means for storing the volume of data on a virtual tape server;

means for receiving a user instruction directing creation of two physical copies of the volume data in response to the construct;

means for receiving at least one construct corresponding to the volume of data from the host;

means for processing the construct in a manner that is substantially transparent to the host to make a determination of whether the volume of data is to be copied to two physical volumes; and

means for selectively initiating creation of two physical copies of the volume of data on the physical volumes according to the determination, wherein neither of the two physical copies shares a physical volume.

2. The virtual tape system of claim 1, wherein the means for storing the volume of data on a virtual tape server is configured to store the volume of data as a first file comprising a first stub portion and a first data portion and to retain the first stub portion after creation of the two physical copies and deletion of at least a subset of the first data portion.

3. The virtual tape system of claim 2, wherein the two physical copies comprise a

primary copy and a secondary copy, the first stub portion corresponding to the primary copy, the virtual tape system further comprising a means for storing a second stub portion corresponding to the secondary copy on the virtual tape server.

4. The virtual tape system of claim 1, wherein the means for processing the construct is configured to find a volume management action that corresponds to the construct in a construct database maintained in a library manager independent of the host, the construct database comprising a plurality of constructs and a plurality of volume management actions associated with the constructs.

5. A virtual tape system configured to store data from a host on a plurality of physical volumes, the virtual tape system comprising:

one or more tape drive units, each of which is configured to write to at least one of the physical volumes;

a virtual tape server configured to receive a volume of data and at least one construct corresponding to the volume of data from the host; and

a library manager configured to process the construct in a manner that is substantially transparent to the host to selectively initiate creation of two physical copies of the volume of data on the physical volumes, wherein neither of the two physical copies shares a common physical volume.

6. The virtual tape system of claim 5, wherein the virtual tape server is further configured to store the volume of data as a first file comprising a first stub portion and a first data portion and to retain the first stub portion after creation of the two physical copies and deletion of at least a subset of the first data portion.

7. The virtual tape system of claim 6, wherein the two physical copies comprise a primary copy and a secondary copy, the first stub portion corresponding to the primary copy, wherein the virtual tape server is further configured to store a second stub portion corresponding to the secondary copy.

8. The virtual tape system of claim 5, wherein the library manager comprises a volume database configured to store a plurality of constructs including the construct received from the host, and a plurality of volume management actions associated with the plurality of constructs.

9. The virtual tape system of claim 8, wherein the construct comprises a management class that specifies a relative importance of recoverability of the volume of data from the tape drive units.

10. The virtual tape system of claim 8, wherein the construct comprises a management class that specifies a secondary pool designator.

11. The virtual tape system of claim 5, wherein the virtual tape server comprises a hierarchical storage manager database containing a plurality of object identities, each of the object identities associated with a volume of data stored on the tape drive units, the hierarchical storage manager database further containing an object location associated with each of the object identities to specify a location of each of the object identities on the tape drive units.

12. A virtual tape server for a virtual tape system configured to store data from a host on a plurality of physical volumes, the virtual tape server comprising:

a processor;

a virtual tape drive configured to receive and store a volume of data from the host; and

a memory configured to store computer code comprising;

a file system manager configured to receive a construct corresponding to the volume of data from the host; and

a hierarchical storage manager configured to transmit the volume of data to one or more physical volumes to create two physical copies of the volume of data in response to a determination of a library manager that two physical copies of the volume of data are to be created in response to a user instruction directing creation of two physical copies of the volume data for the construct, wherein the determination is made by processing the construct in a manner that is substantially transparent to the host and neither of the two physical copies shares a common physical volume.

13. The virtual tape server of claim 12, wherein the virtual tape drive is further configured to store the volume of data as a first file comprising a first stub portion and a first data portion and to retain the first stub portion after creation of the two physical copies and deletion of at least a subset of the first data portion.

14. The virtual tape server of claim 13, wherein the two physical copies comprise a primary copy and a secondary copy, the first stub portion corresponding to the primary copy, the virtual tape drive further configured to store a second stub portion corresponding to the secondary copy.

15. The virtual tape system of claim 12, further comprising an automated storage manager administrator configured to transmit the construct to the library manager and to receive a command to initiate creation of two physical copies of the volume of data from the library manager.

16. A library manager for a virtual tape system configured to store data from a host on a plurality of physical volumes, the library manager comprising:

a processor; and

a memory configured to store computer code comprising;

a construct database comprising a plurality of constructs and volume management actions, each of which is associated with at least one of the constructs; and

a construct manager configured to read the construct database to determine which of the volume management actions is associated with one of the constructs that corresponds to a volume of data within a virtual tape server of the virtual tape system,

a command processor configured to direct the virtual tape system to initiate creation of two physical copies of the volume of data from the virtual tape server in response to a determination that the volume management action associated with the construct corresponding to the volume of data specifies that two physical copies should be created, wherein neither of the two physical copies shares a physical volume.

17. The library manager of claim 16, the construct manager further configured to modify associations of volume management actions and constructs in response to user input independent of the host.

18. The library manager of claim 17, wherein the construct manager is configured to receive the user input via a control console that is only directly coupled to the library manger.

19. The library manager of claim 16, wherein the construct that corresponds to a volume of data within the virtual tape server comprises a management class that specifies a relative importance of recoverability of the volume of data.

20. The library manager of claim 16, wherein the construct that corresponds to a volume of data within the virtual tape server comprises a secondary pool designator.

21. A method for storing data from a host on a plurality of physical volumes of a virtual tape system, the method comprising:

receiving a volume of data from the host;

storing the volume of data on a virtual tape server;

receiving at least one construct corresponding to the volume of data from the host;

receiving a user instruction directing creation of two physical copies of the volume data in response to the construct;

processing the construct in a manner that is substantially transparent to the host to make a determination of whether the volume of data is to be copied to two physical volumes; and

selectively initiating creation of two physical copies of the volume of data on the physical volumes according to the determination, wherein neither of the two physical copies shares a physical volume.

22. The method of claim 21, wherein the volume of data comprises a stub portion and a data portion, the method further comprising:

deleting at least a subset of the data portion from the virtual tape server; and

retaining the stub portion after creation of the two physical copies and deletion of at least a subset of the data portion from the virtual tape server.

23. The method of claim 22, wherein the two physical copies comprise a primary copy and a secondary copy, the first stub portion corresponding to the primary copy, the method further comprising storing a second stub portion corresponding to the secondary copy in the virtual tape server.

24. The method of claim 21, wherein processing the construct comprises finding a volume management action that corresponds to the construct in a construct database maintained in a library manager independent of the host, the construct database comprising a plurality of constructs and a plurality of volume management actions associated with the constructs.

25. A computer readable medium comprising computer code configured to carry out a method for storing data from a host on a plurality of physical volumes of a virtual tape system, the method comprising:

receiving a volume of data from the host;

storing the volume of data on a virtual tape server;

receiving at least one construct corresponding to the volume of data from the host;

receiving a user instruction associating the construct with a volume management action directing creation of two physical copies of the volume data; and

closing the volume of data on the virtual tape server;

processing the construct in a manner that is substantially transparent to the host to make a determination of whether the volume of data is to be copied to two physical volumes; and

selectively initiating creation of two physical copies of the volume of data on the physical volumes according to the determination, wherein neither of the two physical copies shares a physical volume.

26. The computer readable medium of claim 25, wherein the volume of data comprises a stub portion and a data portion, the method further comprising:

deleting at least a subset of the data portion from the virtual tape server; and

retaining the stub portion after creation of the two physical copies and deletion of at least a subset of the data portion from the virtual tape server.

27. The computer readable medium of claim 26, wherein the two physical copies comprise a primary copy and a secondary copy, the first stub portion corresponding to the primary copy, the method further comprising storing a second stub portion corresponding to the secondary copy in the virtual tape server.

28. The computer readable medium of claim 25, wherein processing the construct comprises finding the volume management action that corresponds to the construct in a construct database maintained in a library manager independent of the host, the construct database comprising a plurality of constructs and a plurality of volume management actions associated with the constructs.