Storage device and method for controlling the storage device

A method for controlling a storage device,

• the storage device including an optical module performing optical communication, and
• receiving a data I/O request transmitted from another device via the optical module, and performing I/O processing responding to the data I/O request to a storage unit being communicably connected,
• the optical module including a light emitting element that generates signal light to be transmitted to the another device and a light receiving element that receives the signal light transmitted from the another device,
• wherein the storage device performs the steps of:
• upon receiving a data write request as the data I/O request from the another device, transmitting a reception enabled notification being information indicating a state where reception of write data for the data write request is enabled to the another device, and starting timing of a write monitoring timer being a timer that monitors timeout of the write data;
• upon timeout of the write monitoring timer, acquiring emitted light quantity of the light emitting element;
• and
• outputting information indicating the acquired emitted light quantity.