Patent ID: 7512679

Claim:
A method to select a captain control node from a plurality of control nodes, comprising the steps of: supplying a plurality of host computers, wherein a different one of said plurality of control nodes is disposed in each of said plurality of host computers, and wherein each host computer comprises a storage management program to manage the transfer of data to data storage and retrieval systems; supplying a plurality of data storage and retrieval systems, wherein each data storage and retrieval system comprises a plurality of host adapters, a plurality of data storage devices, a processor, and a data cache; supplying a communication link interconnecting each of said plurality of host computers and each of said data storage and retrieval systems; sending by each of said plurality of control nodes a first signal to each of the other control nodes; receiving by each of said plurality of control nodes, a response signal from each of the other control nodes; determining by each of said plurality of control nodes individual response times for each of the other control nodes; determining an aggregate response time for each of the plurality of interconnected control nodes; determining whether to select a captain control node using said aggregate response times; operative if the captain control node is selected using said aggregate response times: determining a minimum aggregate response time; and determining if two or more control nodes each have said minimum aggregate response time; if two or more control nodes each have said minimum aggregate response time, repeating said providing, receiving, calculating, and determining steps; designating a control node having said minimum aggregate response time as the captain control node to coordinate the operations of said plurality of host computers; calculating by each of said plurality of control nodes a standard deviation for that control node's aggregate response time; providing said standard deviation by each control node to each of the remaining control nodes.