Virtual logical unit state maintenance rules engine

• US 20060080416A1
• Filed: 08/31/2004
• Published: 04/13/2006
• Est. Priority Date: 08/31/2004
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Gandhi, Shreyas P.
• Granted Patent: US 7,516,214 B2
• Time in Patent Office: Days
• US Class Current: 709/220
• CPC Class Codes: G06F 16/90344 by using string matching techniques

Abstract

A rules engine is provided to enhance management capability in storage area networks and particularly within storage switches. Resulting state and status information for virtual logical units can be maintained in a database. The database can be indexed according to the current state and/or status of members of a virtual logical unit. When an event associated with a physical target of a virtual logical unit is detected, the current state and status of members of the virtual logical unit can be determined. The current state and status information can be maintained in dynamic state and status indicator. The current state and status information can be used to identify a corresponding entry in the rules database. From the rules database, the proper resulting status and/or state of the members and/or the virtual logical unit can be determined.

Claims

1. A method of managing virtual logical units, comprising:

detecting an event associated with at least one first member of a first virtual logical unit configuration;

determining a resulting status of said at least one first member as a result of said event;

accessing current state and status information for at least one second member of said first virtual logical unit; and

determining a resulting status of said first virtual logical unit from a rules database, wherein said current state and status information for said at least one second member and said resulting status of said at least one first member are used to index into said rules database.

2. The method of claim 1, further comprising:

formulating a key from said resulting status of said at least one first member and said current state and status information for said at least one second member.

3. The method of claim 2, wherein said step of determining a resulting status of said first virtual logical unit comprises:

accessing said rules database;

matching said key to a key index in said rules database to determine an entry corresponding to said resulting status of said at least one first member and said current state and status information for said at least one second member;

determining said resulting status of said first virtual logical unit from said entry in said rules database.

4. The method of claim 2, further comprising:

determining a resulting state of said at least one first member and a resulting state and status of said at least one second member from said rules database, wherein said current state and status information for said at least one second member and said resulting status of said at least one first member are used to index into said rules database.

5. The method of claim 4, wherein said step of determining a resulting state of said at least one first member and a resulting state and status of said at least one second member comprises:

accessing said rules database;

matching said key to a key index in said rules database to determine an entry corresponding to said resulting status of said at least one first member and said current state and status information for said at least one second member;

determining said resulting state of said at least one first member and said resulting state and status of said at least one second member from said entry in said rules database.

6. The method of claim 1, wherein said step of accessing state and status information for at least one second member of said first virtual logical unit includes:

accessing a dynamic state and status indicator for said first virtual logical unit, said dynamic state and status indicator is dynamically updated to reflect a current state and status of each member of said first virtual logical unit.

7. The method of claim 1, wherein:

said first virtual logical unit is a clustered virtual logical unit.

8. The method of claim 7, wherein:

said clustered virtual logical unit includes a first instance of a virtual logical unit provisioned at a first storage switch a second instance provisioned at a second storage switch.

9. The method of claim 8, wherein:

said at least one first member includes a local portion provisioned at said first storage switch and a remote portion provisioned at said second storage switch;

said at least one second member includes a local portion provisioned at said second storage switch and a remote portion provisioned at said first storage switch.

10. The method of claim 9, wherein:

said at least one first member represents the virtualization of one or more physical logical units coupled to said first storage switch; and

said at least one second member represents the virtualization of one or more physical logical units coupled to said second storage switch.

11. The method of claim 1, wherein:

said resulting status of said at least one first member includes at least one of online and offline.

12. The method of claim 1, wherein:

said current state information for said at least one second member includes at least one of synchronized, needs synchronization, and being synchronized.

13. A storage switch, comprising:

a first virtual logical unit configuration including at least one first member and at least one second member;

a state and status indicator for said first virtual logical unit configuration, said state and status indicator is updated to reflect a current state and status of each member of said first virtual logical unit configuration;

a rules database including resulting status information for said first virtual logical unit configuration, said resulting status information is indexed in said rules database based upon an event associated with said first virtual logical unit configuration and a current state and status of each member of said first virtual logical unit configuration; and

a management module adapted to receive an indication of an event associated with said at least one first member of said first virtual logical unit configuration, wherein said management module, upon receipt of an indication, determines resulting status information for said first virtual logical unit configuration using said state and status indicator and said rules database.

14. The storage switch of claim 13, wherein:

said rules database includes a plurality of entries and a key index for said plurality of entries;

said key index, for each of said entries, includes a first field for the current state of said at least one first member, a second field for the current state of said at least one second member, and a third field for the current status of said at least one second member.

15. The storage switch of claim 14, wherein:

said rules database includes a first portion for offline to online member transitions and a second portion for online to offline member transitions.

16. The storage switch of claim 14, wherein:

said key index further includes a fourth field for the current status of said at least one first member.

17. The storage switch of claim 16, wherein:

said rules database includes entries for offline to online member transitions and entries for online to offline member transitions.

18. The storage switch of claim 17, wherein:

said fourth field denotes a current state of said at least one first member as online for each entry in said rules database corresponding to offline to online member transitions;

said fourth field denotes a current state of said at least one first member as offline for each entry in said rules database corresponding to online to offline member transitions.

19. The storage switch of claim 13, wherein, upon receiving an indication, said management module:

accesses said state and status indicator to determine current state and status information for said at least one second member and current state information for said at least one first member;

formulates a key using said current state and status information;

matches said key to a key index in said rules database to determine an entry corresponding to said current state and status information for said at least one second member and said current state information for said at least one first member;

determines resulting status information for said first virtual logical unit from said entry in said rules database.

20. The storage switch of claim 19, wherein:

said rules database further includes resulting state and status information for said at least one second member and resulting state information for said at least one first member; and

said management module, upon receiving an indication, further determines resulting state information for said at least one first member and resulting state and status information for said at least one second member from said entry in said rules database.

21. A method, comprising:

providing a dynamic state and status indicator for at least one first member of a virtual logical unit; and

providing a table of resulting state and status information for said virtual logical unit, said resulting state and status information includes a plurality of entries of resulting state and status information indexed according to at least a current state and status of a non-event member of said virtual logical unit.

22. The method of claim 21, wherein:

said virtual logical unit includes at least one second member.

23. The method of claim 22, wherein:

said plurality of entries are further indexed according to a resulting status of an event member of said virtual logical unit.

24. The method of claim 23, further comprising:

detecting an event associated with said at least one second member and determining a status of said at least one second member;

classifying said at least one second member as an event member;

determining current state and status information for said at least one first member from said dynamic state and status indicator;

matching an entry in said table based on said current state and status information for said at least one first member and said status of said at least one second member; and

determining a resulting status of said virtual logical unit from said matching entry.

25. One or more processor readable storage devices having processor readable code embodied on said one or more processor readable storage devices, said processor readable code for programming one or more processors to perform a method comprising:

detecting an event associated with at least one first member of a first virtual logical unit configuration;

determining a resulting status of said at least one first member as a result of said event;

accessing current state and status information for at least one second member of said first virtual logical unit; and

determining a resulting status of said first virtual logical unit from a rules database, wherein said current state and status information for said at least one second member and said resulting status of said at least one first member are used to index into said rules database.

26. One or more processor readable storage devices according to claim 25, wherein said method further comprises:

formulating a key from said resulting status of said at least one first member and said current state and status information for said at least one second member.

27. One or more processor readable storage devices according to claim 26, wherein said step of determining a resulting status of said first virtual logical unit comprises:

accessing said rules database;

matching said key to a key index in said rules database to determine an entry corresponding to said resulting status of said at least one first member and said current state and status information for said at least one second member; and

determining said resulting status of said first virtual logical unit from said entry in said rules database.

28. One or more processor readable storage devices according to claim 26, wherein said method further comprises:

determining a resulting state of said at least one first member and a resulting state and status of said at least one second member from said rules database, wherein said current state and status information for said at least one second member and said resulting status of said at least one first member are used to index into said rules database.

29. One or more processor readable storage devices having processor readable code embodied on said one or more processor readable storage devices, said processor readable code for programming one or more processors to perform a method comprising:

providing a dynamic state and status indicator for at least one first member of a virtual logical unit; and

providing a table of resulting state and status information for said virtual logical unit, said resulting state and status information includes a plurality of entries of resulting state and status information indexed according to at least a current state and status of a non-event member of said virtual logical unit.