Method to automatically determine host to LUN (logical unit number) path availability for multi path attached storage systems

• US 8,332,505 B2
• Filed: 03/04/2008
• Issued: 12/11/2012
• Est. Priority Date: 03/04/2008
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: LSI Corporation (Broadcom, Inc.)
• Inventors: Hagerott, Steven G., Tefft, Glenn, Ziegler, Mark, Stankey, Robert R. Jr.
• Primary Examiner(s): Whipple, Brian P
• Assistant Examiner(s): BELCHER, HERMAN A
• Application Number:
  US12/074,509
• Publication Number:
  US 20090228748A1
• Time in Patent Office: 1,743 Days
• Field of Search: 709/224
• US Class Current: 709/224
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: G06F 11/2215 to test error correction or detection circuits

Abstract

The present disclosure provides testing of a storage system. The test may compare the storage array controller LUNs which may be configured to be accessible by a host with the LUNs which are currently available to prevent a zero path scenario from occurring. The test may verify at least one path exists for each LUN to a storage controller of a storage array before injecting an error into another storage controller of the storage array. The present disclosure also provides verification of the configuration of a storage system. The configuration verification may verify that the storage array controller LUNs which are configured to be accessible by a host are actually accessible by the host. If the configuration verification is unable to verify the configuration of storage system, the configuration verification may display an error.

Claims

1. A method, comprising:

running a test on a storage system comprising a host and a storage array;

generating a first set of at least one path configured to be accessible between a LUN (logical unit number) of said storage array and said host;

generating a second set of at least one path accessible between said LUN of said storage array and said host;

comparing the first set to the second set;

determining a path of said first set associated with a first controller of said storage array is present in said second set prior to injecting a fault to a second controller of said storage array;

injecting said fault to said second controller of said storage array;

recovering said second controller of said storage array from said fault;

updating said second set of at least one path accessible between said LUN of said storage array and said host;

determining a path of said first set associated with said second controller of said storage array is present in said second set prior to injecting an additional fault to said first controller of said storage array;

injecting said additional fault to said first controller of said storage array;

recording a first time when recovering said second controller of said storage array;

recording a second time when determining a path of said first set associated with said second controller of said storage array is present in said second set;

measuring a time difference between said first time and said second time; and

optimizing the test based upon the measured time difference.

2. The method as claimed in claim 1, wherein said generating a first set of at least one path configured to be accessible between a LUN (logical unit number) of said storage array and said host comprises:

querying said storage array to determine a WWN (world wide name) of said storage array, a WWN for each LUN of said storage array, and a WWN of a HBA (host bus adapter) associated with each one of said each LUN of said storage array; and

querying said host to determine a network address of said host associated with said WWN of said HBA.

3. The method as claimed in claim 2, wherein said querying said storage array comprises:

querying said storage array utilizing a remote procedure call (RPC) application programming interface (API).

4. The method as claimed in claim 1, wherein said generating a first set of at least one path configured to be accessible between a LUN (logical unit number) of said storage array and said host comprises:

obtaining a WWN (world wide name) of said storage array from a first input to said test; and

obtaining a network address of said host associated with said WWN of said HBA from a second input to said test.

5. The method as claimed in claim 1, wherein said generating a second set of at least one path accessible between said LUN of said storage array and said host comprises:

querying a failover driver of said host to generate said second set of at least one path accessible between said LUN of said storage array and said host.

6. The method of claim 1, wherein said determining a path of said first set associated with a first controller of said storage array is present in said second set prior to injecting a fault to a second controller of said storage array comprises:

locking said second controller wherein said fault cannot be injected to said second controller when said second controller is locked;

determining a path of said first set associated with a first controller of said storage array is present in said second set; and

unlocking said second controller.

7. The method of claim 6, wherein said second controller is locked utilizing a semaphore associated with said second controller.

8. The method of claim 1 wherein said determining a path of said first set associated with said second controller of said storage array is present in said second set prior to injecting an additional fault to said first controller of said storage array comprises:

locking said first controller wherein said additional fault cannot be injected to said first controller when said first controller is locked;

determining a path of said first set associated with a second controller of said storage array is present in said second set; and

unlocking said first controller.

9. The method of claim 8, wherein said second controller is locked utilizing a semaphore associated with said second controller.

10. Computer executable instructions, embodied in a non-transitory media, for performing a method comprising:

running a test on a storage system comprising a host and a storage array;

generating a first set of at least one path configured to be accessible between a LUN (logical unit number) of said storage array and said host;

generating a second set of at least one path accessible between said LUN of said storage array and said host;

comparing the first set to the second set;

determining a path of said first set associated with a first controller of said storage array is present in said second set prior to injecting a fault to a second controller of said storage array;

injecting said fault to said second controller of said storage array;

recovering said second controller of said storage array from said fault;

updating said second set of at least one path accessible between said LUN of said storage array and said host;

determining a path of said first set associated with said second controller of said storage array is present in said second set prior to injecting an additional fault to said first controller of said storage array;

injecting said additional fault to said first controller of said storage array;

recording a first time when recovering said second controller of said storage array;

recording a second time when determining a path of said first set associated with said second controller of said storage array is present in said second set;

measuring a time difference between said first time and said second time; and

optimizing the test based upon the measured time difference.