Method and apparatus for analyzing a storage network based on incomplete information from multiple respective controllers

• US 6,314,460 B1
• Filed: 10/30/1998
• Issued: 11/06/2001
• Est. Priority Date: 10/30/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Nicholson, Robert Bruce, Knight, Greg
• Primary Examiner(s): Barot, Bharat
• Application Number:
  US09/183,711
• Time in Patent Office: 1,103 Days
• Field of Search: 709/212-213, 709/217-219, 709/220-225, 709/229, 711/100-101, 711/105, 711/111, 725/88-93, 725/100, 345/335, 345/508
• US Class Current: 709/220
• CPC Class Codes: G06F 11/3495 for systems
• CPC Class Codes: G06F 3/0626 Reducing size or complexity of storage systems
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: H04L 41/044 comprising hierarchical management structures
• CPC Class Codes: H04L 41/046 comprising network management agents or mobile agents therefor
• CPC Class Codes: H04L 41/0853 by actively collecting configuration information or by backing up configuration information

Abstract

An analyzer for a storage network attached to a host computer system through multiple controllers receives information from each controller concerning a shared storage network bus, and resolves incomplete information received from one controller using information received by another controller. Unknown devices are resolved by selecting devices known to multiple controllers as cross-reference objects, determining sets of possible placements for an unresolved device, and finding one possible placement common to each set. Preferably, the network analyzer is part of a larger distributed storage management program which supports management of storage networks connected to multiple host computer systems through one or more controllers in each respective host, the distributed management program comprising a central manager and a separate agent in each host, the analyzer being part of the agent. Each agent independently collects data from the network(s) attached to its host, analyzes the network(s), builds data structures representing the network(s), and uses the data structures to service information requests from the central manager.

Claims

1. A method for analyzing a storage network, said storage network comprising a plurality of controllers attached to a common storage network communication medium, and a plurality of data storage devices attached to said common storage network communication medium, said method comprising the steps of:

(a) obtaining information from each of said controllers concerning devices attached to said common storage network communication medium, wherein information obtained from each respective controller is incomplete;

(b) identifying a device to be resolved, said device to be resolved being known to a first controller, but being unknown to a second controller;

(c) selecting a plurality of devices attached to said common storage network communication medium as cross-reference objects;

(d) determining, for each respective cross-reference object selected by said selecting step, a corresponding set of possible placements for said device to be resolved; and

(e) identifying a single possible placement common to each respective set of possible placements as the resolved placement of said device to be resolved.

2. The method for analyzing a storage network of claim 1, further comprising the step of:

(f) constructing a structured data representation of said storage network, said structured data representation containing at least one record corresponding to each respective physical device attached to said storage network.

3. The method for analyzing a storage network of claim 2, wherein said records corresponding to physical devices are linked to each other in a relationship corresponding to connections among devices attached to said storage network.

4. The method for analyzing a storage network of claim 1, wherein said device to be resolved is said first controller.

5. The method for analyzing a storage network of claim 1, wherein said selecting step selects two devices as cross-reference objects.

6. The method for analyzing a storage network of claim 1, further comprising the step of:

(f) transmitting information determined as a result of steps (a) through (e) to a central manager for said storage network, said central manager receiving information from a plurality of host computer systems.

7. A computer program product for analyzing a storage network, said storage network comprising a storage network communication medium and a plurality of data storage devices, said computer program product including a plurality of computer executable instructions stored on a computer readable medium, wherein said instructions, when executed by said computer, cause the computer to perform the steps of:

(a) obtaining information from each of said controllers concerning devices attached to said common storage network communication medium, wherein information obtained from each respective controller is incomplete;

(b) identifying a device to be resolved, said device to be resolved being known to a first controller, but being unknown to a second controller;

(c) selecting a plurality of devices attached to said common storage network communication medium as cross-reference objects;

(d) determining, for each respective cross-reference object selected by said selecting step, a corresponding set of possible placements for said device to be resolved; and

(e) identifying a single possible placement common to each respective set of possible placements as the resolved placement of said device to be resolved.

8. The computer program product of claim 7, wherein said instructions, when executed by said computer, further cause the computer to perform the step of:

(f) constructing a structured data representation of said storage network, said structured data representation containing at least one record corresponding to each respective physical device attached to said storage network.

9. The computer program product of claim 8, wherein said records corresponding to physical devices are linked to each other in a relationship corresponding to connections among devices attached to said storage network.

10. The computer program product of claim 7, wherein said device to be resolved is said first controller.

11. The computer program product of claim 7, wherein said selecting step selects two devices as cross-reference objects.

12. The computer program product of claim 7, wherein said instructions, when executed by said computer, further cause the computer to perform the step of:

(f) transmitting information determined as a result of steps (a) through (e) to a central manager for said storage network, said central manager receiving information from a plurality of host computer systems.