Consolidating non-volatile memory across multiple storage devices for front end processing

A method comprising:

• coupling a host device to an array of data storage devices, the host device comprising a host processor circuit and host memory, each of the data storage devices comprising a primary non-volatile memory (NVM) of a first type, a secondary NVM of a different, second type, and a controller circuit comprising a top level controller and a secondary controller;
• transferring data between the host device and the array of data storage devices during a normal I/O processing mode by issuing access commands from the host device o the controller circuits of the respective data storage devices in the array to transfer data sets between the respective primary and secondary NVMs and a host device memory, the top level controller in each data storage device determining a target location for each data set;
• and
• using the host device to enact a front end I/O processing mode in which the host device takes control of, and the associated top level controller relinquishes control over, the secondary NVM of each of the data storage devices to form a consolidated, distributed memory space;
• and
• transferring data between the host device and the array of data storage devices during the front end I/O processing mode to transfer data to the consolidated, distributed memory space using the secondary controller of each data storage device in the array.