Embodiments of the present invention disclose methods and systems for object storage. Migration policies and an algorithm applied by the module facilitates the migration of files (i.e., object replicas or erasure code fragments) from one storage to another storage. The FILE_HEAT is monitored over a period of time. If the FILE_HEAT of a file increases over a period of time relative to the other files, the file is migrated to a higher level storage. Files can be migrated to a higher level storage even if the FILE_HEAT of a file decreases over a period of time.