A system, comprising: a processor ; a memory coupled to the processor ; a storage device coupled to the processor , the storage device including a storage for data, a controller to manage the data in the storage , a first interface (440-1) configured to enable access to the storage device using a block mode, and a second interface (440-2) configured to enable access to the storage device using a direct access for files, DAX, mode , the storage device configured to extend the memory , wherein the storage device includes a Solid State Drive, SSD; and an operating system to offer block mode when a command issued by an application is a block mode command and to offer DAX mode when a command issued by the application is a DAX command , wherein the operating system comprises: a mode switch to select one of the first interface (440-1) and the second interface (440-2) for an issued DAX command based at least in part on one of a parameter of the operating system , a metadata of a file or a data size associated with the command; a modifier to convert the issued DAX command to a block mode command when the selected interface is the first interface (440-1); and a transmitter to transmit the converted command to the storage device using the selected first interface (440-1), and wherein the controller is configured to process the transmitted command (415; 455). a processor ; a memory coupled to the processor ; a storage device coupled to the processor , the storage device including a storage for data, a controller to manage the data in the storage , a first interface (440-1) configured to enable access to the storage device using a block mode, and a second interface (440-2) configured to enable access to the storage device using a direct access for files, DAX, mode , the storage device configured to extend the memory , wherein the storage device includes a Solid State Drive, SSD; and an operating system to offer block mode when a command issued by an application is a block mode command and to offer DAX mode when a command issued by the application is a DAX command , wherein the operating system comprises: a mode switch to select one of the first interface (440-1) and the second interface (440-2) for an issued DAX command based at least in part on one of a parameter of the operating system , a metadata of a file or a data size associated with the command; a modifier to convert the issued DAX command to a block mode command when the selected interface is the first interface (440-1); and a transmitter to transmit the converted command to the storage device using the selected first interface (440-1), and wherein the controller is configured to process the transmitted command (415; 455). a mode switch to select one of the first interface (440-1) and the second interface (440-2) for an issued DAX command based at least in part on one of a parameter of the operating system , a metadata of a file or a data size associated with the command; a modifier to convert the issued DAX command to a block mode command when the selected interface is the first interface (440-1); and a transmitter to transmit the converted command to the storage device using the selected first interface (440-1), and wherein the controller is configured to process the transmitted command (415; 455). <EOS>