Patent ID: 6959360

Claim:
A data storage system that is accessed by one or more applications executing on a host system that is connected to a communication network, the data storage system comprising: a first storage subsystem having a first disk controller configured to connect to the communication network and operative to service read and write commands relating to I/O requests from the host; at least a second storage subsystem having a second disk controller configured to connect to the communication network and operative to service read and write commands relating to I/O requests from the host; and a storage manager in data communication with the first storage subsystem and with the second storage subsystem and operative to: obtain input/output (I/O) activity information of volumes in the first storage subsystem; obtain input/output (I/O) activity information of volumes in the second storage subsystem; obtain volume information for a first application which is executing on the host system that identifies volumes in the first storage subsystem and in the second storage subsystem that are accessed by the first application; selectively initiate a first transfer of data from a selected volume in the first storage subsystem that is associated with the first application to a target volume in the first storage subsystem, based on I/O activity of the selected volume and on whether or not there is a free volume in the first storage system that can serve as the target volume; and selectively initiate a second transfer of data from a selected volume in the second storage subsystem that is associated with the first application to a target volume in the second storage subsystem, based on I/O activity of the selected volume and on whether or not there is a free volume in the second storage system that can serve as the target volume, wherein if one of the first or second transfers of data cannot be initiated, then the other transfer of data will not be initiated.