1. An apparatus to collocate data, the apparatus comprising: a mode module configured to set a collocation mode of a storage pool comprising a plurality of storage pool volumes configured to store data, wherein the collocation mode is configured to specify the granularity of data to be collocated; an assignment module configured to assign a source comprising data to a collocation group; and a collocation module configured to collocate the source's data to a minimum number of storage pool volumes based on the collocation mode of the storage pool and collocation group assignment of the source.