Patent ID: 8868863

Claim:
A file server apparatus including a plurality of disparate storage systems for storing a file image including a plurality of file image blocks, the apparatus comprising: a data storage; and a processor communicatively coupled to the data storage, the processor configured to: maintain, in the data storage, a first set of file block locations of at least a first portion of the plurality of file image blocks that are located in a first storage system of the plurality of disparate storage systems; and maintain, in the data storage, a second set of file block locations of at least a second portion of the plurality of file image blocks that are located in a second disparate storage system of the plurality of disparate storage systems; wherein at least a plurality of in-use file blocks corresponding to the second set of file block locations are maintained in the second disparate storage system based on a plurality of eviction times that are corresponding to the plurality of in-use blocks and based on a cost optimization; and wherein the cost optimization is based on a first data access monetary cost and a first data storage monetary cost associated with fetching at least a portion of the plurality of in-use file blocks from the first storage system and a second data access monetary cost and a second data storage monetary cost associated with fetching at least a portion of the plurality of in-use file blocks from the second storage system.