Patent ID: 7069276

Claim:
A computer system comprising: a front-end server connected to a network and adapted to receive requests from one or more client computers; a first back-end server connected to said front-end server and said client computers via said network and operative to receive I/O requests from said front-end server; a second back-end server connected to said front-end server and said client computers via said network and operative to receive I/O requests from said front-end server; a first plurality of storage units initially accessible by said first back-end server and not accessible by said second back-end server; a second plurality of storage units initially accessible by said second back-end server and not accessible by said first back-end server; a managing computer in data commnunication with said front-end server and said back-end servers via said network, said managing computer operative to obtain data access load conditions at each storage unit from said front-end server; a storage system, said storage system comprising said first plurality of storage units and said second plurality of storage units, wherein a communication port in said first back-end server and a communication port in said second back-end server can be configured for data communication with communication ports in said storage system; and a switch operative for data communication among devices connected to said switch, said first back-end server and said second back-end server being connected to said switch, said storage system being connected to said switch so that said first and second back-end servers can access data stored in said first and second plurality of storage units, said switch further being operative to direct data requests from one of said first and second back-end servers to a specified storage unit in said storage system, wherein, based on said data access load conditions, including a condition in that a load at a source storage unit in said first plurality of storage units exceeds a predetermined amount, said managing computer operative to: select a destination storage unit in said second plurality of storage units; copy a first data partition from said source storage unit to said destination storage unit and subsequently delete said first data partition from said source storage unit; grant said first back-end server access to said destination storage unit; and transmit information to said front-end server that said first data partition is to be accessed by said first back-end server via said destination storage unit.