Patent ID: 8578113

Claim:
A method for managing extents in a data storage system, the method comprising: monitoring usage statistics for extents residing on at least one normally powered-up storage device; identifying, using the usage statistics, “cold” extents in the at least one normally powered-up storage device that have not been accessed for a specified period of time; automatically compressing the “cold” extents and migrating the “cold” extents from the at least one normally powered-up storage device to an intermediate repository, the intermediate repository storing “cold” extents in preparation for migration to at least one normally powered-down storage device; automatically migrating the “cold” extents from the intermediate repository to the at least one normally powered-down storage device in the event the amount of data in the intermediate repository reaches a specified level; and automatically migrating extents from the at least one normally powered-down storage device to the at least one normally powered-up storage device in the event I/O is received for the extents.