System and method for sharing multiple storage arrays by dedicating adapters as primary controller and secondary controller for arrays reside in different host computers

A method for accessing data for a plurality of host computers on a plurality of storage arrays, comprising the steps of:

• a) associating at least one adapter with each host computer;
• b) associating a first adapter, associated with a first host, as a primary controller for a first storage array;
• c) associating a communication interconnect between all of the adapters;
• d) sending a data access request from the first host to the first adapter associated with the host;
• e) identifying whether requested data is stored in the first storage array primarily controlled by the first adapter;
• f) sending a data access request, through the communication interconnect, for the requested data not stored in the first storage array primary controlled by the first adapter to an adapter primarily controlling the storage array having the requested data;
• g) associating the first adapter as a secondary controller for a second storage array said secondary adapter residing in a different host computer than the host computer having the adapter primarily controlling the second storage array;
• h) determining when the first adapter primarily controlling the first storage array is unavailable;
• and
• i) using a second adapter having secondary control for the first storage array as a controller for the first designated storage array when the first adapter having primary control of the first designated storage array is unavailable.

In a networked computer system comprising a plurality of host computers and a plurality of storage arrays, wherein each host computer has an adapter card therein, each adapter card primarily controlling a first storage array and secondarily controlling a second storage array, and having a communication interconnect between all of the adapter cards in the system, a computer program product for use with the adapter cards, comprising:

• a computer usable medium having computer readable program code means embodied in said medium for providing access for all of the host computers to data stored on the plurality of storage arrays, said computer program product having:
• computer readable program code means for a first adapter card associated with a first host computer receiving a data access request from the first host computer;
• computer readable program code means for identifying whether requested data is stored in the storage array primarily controlled by the first adapter;
• computer readable program code means for sending the data access request, through the communication interconnect, for data not stored in the storage array primary controlled by the first adapter to the adapter card primarily controlling the storage array having the requested data;
• and
• computer readable program code means for enabling a secondary adapter residing in a second host computer to take over control of the first array for the first primary adapter when the first primary adapter fails.

An article of manufacture for use in a networked computer system comprising a plurality of host computers and a plurality of storage arrays, wherein each host computer has at least one adapter therein, each adapter card primarily controlling a first storage array and secondarily controlling a second storage array, and having a communication interconnect between all of the adapter cards in the computer system for providing access for all of the host computers to data stored on the plurality of storage arrays, the article of manufacture having a computer program order embodiment in said medium which causes the computer system to:

• send a data access request from a first host computer to a first adapter associated with the first host computer;
• identify whether requested data is stored in a first storage array primarily controlled by the first adapter;
• send the data access request, through the communication interconnect, for the requested data not stored in the first storage array primary controlled by the first adapter, to an adapter primarily controlling the storage array having the requested data;
• determine when the first adapter primarily controlling the first storage array is unavailable;
• and
• use a second adapter having secondary control of the first storage array as a controller for the first designated storage array when the first adapter having primary control of the first designated storage array is unavailable.