Patent ID: 8230123

Claim:
A computer program product for managing data in a plurality of storage devices comprising at least one of a first storage type and a second storage type, the computer program product comprising a computer readable storage medium having computer readable program code embodied therein that executes to perform operations, the operations comprising: processing performance information for a time period for Input/Output (I/O) operations with respect to an extent maintained in at least one of the storage devices of the first storage type, wherein the performance information indicates I/O sizes of data subject to the I/O operations with respect to the extent; determining whether characteristics of the I/O operations other than the I/O sizes indicate that the extent is eligible for migration to at least one of the storage devices of the second storage type; determining characteristics of the I/O sizes of the I/O operations; determining whether the characteristics of the I/O sizes of the I/O operations indicate that the extent should be migrated from the at least one storage device of the first storage type to at least one of the storage devices of the second storage type; and migrating the extent from one of the storage devices of the first type to at least one of the storage devices of the second type in response to determining that the extent is eligible for migration and that the characteristics of the I/O sizes indicate that the extent should be migrated.