Self-configuration of source-to-target mapping

• US 20050081006A1
• Filed: 10/10/2003
• Published: 04/14/2005
• Est. Priority Date: 10/10/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Shackelford, David Michael, Blea, David Randall, Schlomer, Todd B., McBride, Gregory Edward, Brundidge, Jimmie Lee, Calder, Errol Jay
• Granted Patent: US 7,269,701 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/2069 Management of state, configuration or failover

Abstract

A computer program for automatically pairing target resources 20 such as volumes or logical units to source resources 20 containing data to be copied. Available target pools 48, 50, 52, 54 of target volumes are determined eligible for copying based on a technical compatibility and a user-defined metric such as recovery point or recovery time. User defined metrics and a policy to implement the metrics may be stored in a medium and selected by a user. The source volumes are prioritized, and progressively larger segments of the eligible target pools are searched for a target volume that satisfies the technical compatibility and user-defined metric. Where subgroups such as nested volumes are present in the source volumes, subgroups are also prioritized for searching. Where no target volume can be paired, the corresponding source volume is marked as processed and a search begins for the next source volume. An output report includes pairings of source to target volumes and source volumes for which no pairing was made.

Claims

1. A data processing system comprising:

a data storage subsystem;

selection logic, responsive to a detection that a copy command has been invoked, for

automatically identifying at least one target pool, an identified target pool comprising at least one eligible target volume, said selection logic further for one of

determining that a pairing cannot be made, and

automatically pairing each source volume in a source group to a said target volume for each instance that an eligible target volume satisfies at least one technical compatibility with a source volume parameter; and

circuitry for automatically returning a message listing each source volume for which a pairing to an eligible target volume was not made.

2. The data processing system of claim 1 wherein said selection logic for automatically pairing each source volume in a source group to a said target volume in each instance wherein an eligible target volume satisfies at least one technical compatibility with a source volume parameter further comprises for each instance wherein an eligible target volume also satisfies a user-defined metric.

3. The data processing system of claim 2 wherein the user-defined metric comprises at least two metrics and a user policy to implement the at least two metrics.

4. The data processing system of claim 2 further comprising a plurality of user-defined metrics embodied in a computer-readable storage medium from which a user may select at least one.

5. The data processing system of claim 4 wherein the user-defined metrics comprise at least one of a recovery point objective, a recovery time objective, a location, a consistency of underlying data, and an application impact.

6. The data processing system of claim 1 wherein the selection logic for automatically pairing comprises logic for indexing the source volumes, logic for iteratively executing one of listing a source volume as one that could not be paired and pairing a source volume to a selected target volume for each instance that at least one target volume within a pool matches a technical compatibility of the source volume.

7. The data processing system of claim 1 wherein the selection logic further comprises a volume search loop whereby source volumes are prioritized, and for each source volume, at least two subsets of all eligible target volumes are searched for a selected target volume.

8. The data processing system of claim 7 wherein the selection logic further comprises a subgroup loop whereby subgroups of source volumes are prioritized, and for each subgroup, a subset of potential target pools for use therewith is identified.

9. A data processing system as in claim 1 further comprises at least one host data processor coupled to said data storage subsystem through a bus, and where said host data processor comprises said selection logic.

10. A data storage system configurator comprising:

means for receiving a user instruction to replicate a first set of data storage devices,

an interface coupled to the first data storage devices and to at least one pool of target data storage devices;

software for evaluating the at least one pool of target data storage devices for technical compatibility with at least one storage device within the first set of data storage devices to identifying eligible target data storage devices;

software for pairing an eligible data storage device to a device from the first set by iteratively searching subsets of the at least one pool;

software for generating one of a confirmation message and an error message, said error message converted to a user readable form if at least one device of the first set is not paired to a device of the at least one pool.

11. The data storage system configurator of claim 10 further comprising computer readable storage means for storing a user-defined metric, and wherein the software for evaluating further evaluates for consistency with a user-defined metric

12. The data storage system configurator of claim 10 wherein the software for evaluating further comprises software for determining pairings from an existing replica.

13. The data storage system configurator of claim 12 wherein the software for determining pairings from an existing replica further comprises software for deleting pairings relevant to the existing replica but not relevant to the first set of data storage devices.

14. A computer program product embodied in a computer readable media for causing a computer to execute program instructions resulting in execution of a method of selecting a target device to which data may be copied, comprising:

determining a source group comprising at least one source device from which data is to be copied;

automatically selecting at least one target pool comprising at least one target device that is eligible for copying based on at least one technical compatibility with the at least one source device;

for each said source device of the source group, one of automatically pairing said source device to one of said at least one target device from the selected at least one pool of targets, and determining that a pairing cannot be made; and

outputting a message indicating one of;

all source groups devices are paired, and not all source group devices are paired.

15. The computer program product of claim 14 wherein the source group comprises a plurality of source devices, and wherein automatically pairing comprises individually prioritizing the plurality of source devices and performing, for each of the prioritized source devices, one of pairing one target device to one source device and determining that no pairing is available.

16. The computer program product of claim 15 wherein automatically pairing further comprises prioritizing subgroups of source devices.

17. The computer program of claim 16 wherein performing further comprises, for each subgroup, determining which pools of target devices are eligible for pairing with a source device within the subgroup.

18. The computer program of claim 17, further comprising dividing the subgroups into local sets, the local sets comprising:

subgroups fully contained in an existing replica;

subgroups partially contained in an existing replica; and

subgroups not at all contained in an existing replica.

19. The computer program of claim 14 wherein automatically pairing comprises searching for a target device within a first subset of the at least one pool of target devices, and if no match is found within the first subset, searching within a second subset of the at least one pool of target devices.

20. The computer program of claim 19 wherein the second subset comprises all pools of target devices within which at least one target device has already been paired to any source device.

21. The computer program of claim 20 wherein the second subset excludes the pools of target devices that are within the first subset.

22. The computer program of claim 19 wherein the first subset comprises all pools of target devices within which at least one target device has already been paired to a source device within a subgroup of source devices in which a current source device is a part.

23. The computer program of claim 19 wherein automatically pairing further comprises, if no match is found within the second subset of the at least one pool of target devices, searching for a target device within a third subset of the at least one pool of target devices.

24. The computer program of claim 23 wherein the third subset comprises all of the selected at least one target pools that are not within at least one of the first and second subsets.

25. The computer program of claim 14 wherein automatically pairing said source device to one of said at least one target device from the selected at least one pool of targets comprises:

determining all matching target devices that are eligible for copying;

prioritizing said all matching target devices according to closeness of the match, wherein closeness is determined from at least one of technical compatibility and a user-defined metric; and

selecting the closest match to pair with the source device.

26. The computer program of claim 14 further comprising assessing connectivity from the at least one source device to potential pools of target devices and considering only those connected to the source device via a data pathway.

27. The computer program of claim 14 further comprising generating an output report that lists at least one of pairings that were generated and source devices for which a pairing could not be generated.

28. The computer program of claim 14 wherein automatically selecting at least one target pool is additionally based on a user-defined metric.

29. The computer program of claim 28 wherein the user-defined metric comprises at least one of a recovery point objective, a recovery time objective, a location, a consistency among underlying data, and an application impact.

30. The computer program of claim 28 wherein the user-defined metric comprises at least two user-defined metrics that comprise a user policy.

31. The computer program of claim 30 wherein automatically pairing one target device comprises pairing a target device that is optimized according to the user policy.

32. A method of using a computer to select a target resource that matches a host resource comprising:

determining at least one technical compatibility attribute of a host resource;

accessing at least one user-defined metric stored in a computer readable memory;

identifying pools of potential target resources that are connected to the host resource via a data pathway;

searching at least one of the identified pools for a matching target resource that satisfies the at least one technical compatibility attribute and the at least one user-defined metric; and

one of selecting the matching target resource and outputting a message indicating that no matching target resource was found.

33. The method of claim 32 wherein searching each of the identified pools comprises searching a first subset of the pools and, and if the matching target resource is not found within the first subset, searching a second subset of the pools.

34. The method of claim 33 wherein the first subset is excluded from the second subset.

35. The method of claim 32 wherein searching at least one of the identified pools comprises searching all of the identified pools of potential target resources, and further wherein selecting the matching target resource comprises selecting a matching target resource from at least two matching target resources that best matches the host resource.