Providing an upgrade path for an existing data storage system

• US 6,304,942 B1
• Filed: 08/09/1999
• Issued: 10/16/2001
• Est. Priority Date: 08/09/1999
• Status: Expired due to Term

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: LSI Logic Corporation (Broadcom, Inc.)
• Inventors: DeKoning, Rodney Allen
• Primary Examiner(s): Nguyen, Hiep T.
• Application Number:
  US09/370,564
• Time in Patent Office: 799 Days
• Field of Search: 711/114, 711/161, 711/162, 711/165, 711/170, 711/171, 711/172, 714/6, 707/204
• US Class Current: 711/114
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A system and method upgrade an original data storage system into an enhanced data storage system. The original data storage system includes an original storage array controller device and an original storage array. The original data storage system is initially connected to a host system via a host bus and presents to the host system an original logical volume mapping associated with a logical identifier and mapped to a physical data set stored in individual storage devices in the original storage array. An enhanced storage array controller device is operatively connected to the host system via the host bus, and the original storage array controller device and a storage connection device coupled to another storage array are operatively connecting to the enhanced storage array controller device via an intermediate bus. The physical data set of the original storage array is redistributed across a plurality of storage arrays, including the original and the other storage arrays. The enhanced storage array controller device is reconfigured to present to the host system a logical volume mapping associated with the logical identifier mapping to the physical data set redistributed across the plurality of storage arrays.

Claims

1. A method of upgrading a data storage system into an enhanced data storage system, said data storage system including a first storage array controller device operatively connected to a host system and to a first storage array, the method comprising:

interposing an enhanced storage array controller between said first storage array controller and said host system;

operatively connecting a second storage array to a storage connection device;

operatively connecting said storage connection device to said enhanced storage array controller;

redistributing data from said first storage array across a plurality of storage arrays, including said first storage array and said second storage array; and

providing a logical to physical map operative to access data redistributed across said plurality of storage arrays.

2. The method of claim 1 further comprising:

configuring said first storage array controller to operate in a pass-through mode whereby individual devices in the first storage array may be accessed by said enhanced storage array controller.

3. The method of claim 2 wherein said step of configuring said first storage array controller to operate in a pass-through mode further comprises:

configuring said first storage array controller to map individual storage devices in said first storage array to logical identifiers in a one-to-one correspondence.

4. The method of claim 1 wherein said storage connection device further comprises:

an environmental services monitor connecting the individual storage devices of said second storage array to said enhanced array controller wherein said environmental services monitor is configured in a pass-through mode.

5. The method of claim 1 wherein said storage connection device comprises a second storage array controller operating in pass-through mode.

6. The method of claim 1 wherein said enhanced array controller provides more disk channels than said first storage array controller.

7. The method of claim 1 wherein said enhanced array controller provides a higher level of RAID functionality than said first storage array controller.

8. The method of claim 1 further comprising:

storing information describing mapping of redistributed data on a storage device contained in said first and second storage arrays.

9. A method for upgrading a data storage system, said data storage system including a storage array controller operatively connected to a host system and to a storage array, the method comprising:

interposing an enhanced array controller between said storage array controller and said host system;

configuring said storage array controller to operate in pass-through mode; and

creating a logical to physical map operative to allow said enhanced storage array controller to access the physical data set stored in said storage array.

10. The method of clam 9 wherein said enhanced array controller provides a higher level of RAID functionality than said storage array controller.

11. The method of claim 10 wherein said step of configuring said storage array controller further comprises:

configuring said storage array controller to map drives in said storage array to logical identifiers in a one-to-one correspondence.

12. An upgraded data storage system comprising:

an enhanced storage array controller coupled to a host system;

a storage array controller coupled to said enhanced storage array controller wherein said storage array controller is configured to operate in a pass-through mode; and

a storage array coupled to said storage array controller wherein said enhanced storage array controller is configured to access physical data in said storage array associated with a logical identifier.

13. The upgraded data storage system of claim 12 further comprising:

a second storage array controller coupled to said enhanced storage array controller; and

a second storage array coupled to said second storage array controller, wherein said enhanced storage array controller is configured to access a physical data set distributed across a plurality of storage arrays, including said storage array and said second storage array.

14. The upgraded data storage system of claim 13 wherein said storage array further comprises:

configuration data recorded in at least one individual disk within said storage array and said second storage array.

15. The upgraded data storage system of claim 12 wherein said storage array controller is replaced by a connection device configured to operate in a pass-through mode.

16. The upgraded data storage system of claim 12 wherein said storage array controller is replaced by means for passing-through communications in a one-to-one correspondence between said enhanced storage array controller and individual disks in said storage array.

17. An upgraded data storage system coupled to a host system via a host bus, the upgraded data storage system comprising:

a first storage array including first individual storage devices;

a storage array controller that has been configured in accordance with said upgraded data storage system to pass though communications in a one-to-one correspondence to and from said first individual storage devices in said first storage array;

a second storage array including second individual storage devices; and

an enhanced storage array controller operatively connected to said host system via said host bus, said enhanced storage array controller configuring a physical data set across both said first storage array and said second storage array to logically map said physical data across both said first storage array and said second storage array.

18. The upgraded data storage system of claim 17 further comprising:

configuration data recorded on one or more individual storage devices within said first storage array and said second storage array.

19. The upgraded data storage system of claim 17 wherein data stored solely in said first data storage array lacks channel redundancy, and data stored across both said first storage array and said second storage array is channel redundant.