A method embodiment commences upon identifying an on-premises storage area such as a file or virtual disk that is composed of a set of data blocks. A history of data access patterns over the data blocks is determined by observing accesses to the data blocks over time. When offsite storage is demanded (e.g., such as to a cloud-based storage facility), one or more storage objects are formed such that the blocks in a first one of the one or more storage objects comprise the blocks that have been measured to have the highest access rates (e.g., most recently accessed or most frequently accessed). Metadata that serves as a map is stored with the storage objects. A process or thread can access the storage objects in expectation that the most recently accessed or most frequently accessed blocks will be available in the first ones of the one or more storage objects.