An apparatus and associated methodology contemplating an apparatus having a processor-based storage controller. A nontransient, tangible computer memory is configured to store a data file. Computer instructions are stored in the computer memory defining file-level array storage logic that is configured to be executed by the controller to logically containerize the data file in a file-level data set across a plurality of virtual storage containers, and to concurrently flush the virtual storage containers by migrating units of the file-level data set to a plurality of physical storage devices.