Information storage device and its control method

A host device comprising:

• a processing part configured to generate a write-back command for making the control part record the information recorded in the non-volatile memory on the disc-shape storage medium, as for the information storage device having an input part configured to be input with a command, a disc-shape storage medium, a non-volatile memory configured to become a cache memory for the disc-shape storage medium, and a control part configured to perform writing information on the non-volatile memory based on a writing command input in the input part and recording the information recorded in the non-volatile memory on the disc-shape storage medium at a prescribed timing.

A control method of an information storage device comprising:

• a first process in which a command is input, a second process in which information is written on a non-volatile memory which becomes a cache memory for a disc-shape storage medium based on the writing command input in the first process, a third process in which the information recorded in the above non-volatile memory in the second process is recorded on the above disc-shape storage medium at a prescribed timing, and a fourth process in which, based on a write-back command input in the first process, the information recorded in the non-volatile memory is recorded in the above disc-shape storage medium while keeping it in the non-volatile memory as it is.